extras/rya.streams/kafka/src/test/java/org/apache/rya/streams/kafka/processors/join/JoinProcessorIT.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.rya.streams.kafka.processors.join;

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.UUID;

import org.apache.kafka.common.serialization.StringDeserializer;
import org.apache.kafka.common.serialization.StringSerializer;
import org.apache.kafka.streams.processor.StateStoreSupplier;
import org.apache.kafka.streams.processor.TopologyBuilder;
import org.apache.kafka.streams.state.Stores;
import org.apache.rya.api.function.join.LeftOuterJoin;
import org.apache.rya.api.function.join.NaturalJoin;
import org.apache.rya.api.model.VisibilityBindingSet;
import org.apache.rya.api.model.VisibilityStatement;
import org.apache.rya.streams.kafka.KafkaTestUtil;
import org.apache.rya.streams.kafka.KafkaTopics;
import org.apache.rya.streams.kafka.RdfTestUtil;
import org.apache.rya.streams.kafka.processors.ProcessorResult;
import org.apache.rya.streams.kafka.processors.ProcessorResult.BinaryResult;
import org.apache.rya.streams.kafka.processors.ProcessorResult.BinaryResult.Side;
import org.apache.rya.streams.kafka.processors.ProcessorResult.UnaryResult;
import org.apache.rya.streams.kafka.processors.StatementPatternProcessorSupplier;
import org.apache.rya.streams.kafka.processors.join.JoinProcessorSupplier.JoinProcessor;
import org.apache.rya.streams.kafka.processors.output.BindingSetOutputFormatterSupplier.BindingSetOutputFormatter;
import org.apache.rya.streams.kafka.serialization.VisibilityBindingSetSerde;
import org.apache.rya.streams.kafka.serialization.VisibilityBindingSetSerializer;
import org.apache.rya.streams.kafka.serialization.VisibilityStatementDeserializer;
import org.apache.rya.streams.kafka.topology.TopologyFactory;
import org.apache.rya.test.kafka.KafkaTestInstanceRule;
import org.junit.Rule;
import org.junit.Test;
import org.openrdf.model.ValueFactory;
import org.openrdf.model.impl.ValueFactoryImpl;
import org.openrdf.query.algebra.StatementPattern;
import org.openrdf.query.impl.MapBindingSet;

import com.google.common.collect.Lists;

/**
 * Integration tests the methods of {@link JoinProcessor}.
 */
public class JoinProcessorIT {

    @Rule
    public KafkaTestInstanceRule kafka = new KafkaTestInstanceRule(true);

    @Test(expected = IllegalArgumentException.class)
    public void badAllVars() throws IllegalArgumentException {
        new JoinProcessorSupplier(
                "NATURAL_JOIN",
                new NaturalJoin(),
                Lists.newArrayList("employee"),
                Lists.newArrayList("person", "employee", "business"),
                result -> ProcessorResult.make( new UnaryResult(result) ));
    }

    @Test
    public void newLeftResult() throws Exception {
        // Enumerate some topics that will be re-used
        final String ryaInstance = UUID.randomUUID().toString();
        final UUID queryId = UUID.randomUUID();
        final String statementsTopic = KafkaTopics.statementsTopic(ryaInstance);
        final String resultsTopic = KafkaTopics.queryResultsTopic(queryId);

        // Setup a topology.
        final String query = "SELECT * WHERE { "
                + "?person <urn:talksTo> ?employee ."
                + "?employee <urn:worksAt> ?business"
                + " }";
        final TopologyFactory factory = new TopologyFactory();
        final TopologyBuilder builder = factory.build(query, statementsTopic, resultsTopic);

        // Create some statements that generate a bunch of right SP results.
        final ValueFactory vf = new ValueFactoryImpl();
        final List<VisibilityStatement> statements = new ArrayList<>();
        statements.add( new VisibilityStatement(
                vf.createStatement(vf.createURI("urn:Bob"), vf.createURI("urn:worksAt"), vf.createURI("urn:TacoPlace")), "a&b") );
        statements.add( new VisibilityStatement(
                vf.createStatement(vf.createURI("urn:Charlie"), vf.createURI("urn:worksAt"), vf.createURI("urn:BurgerJoint")), "a") );
        statements.add( new VisibilityStatement(
                vf.createStatement(vf.createURI("urn:Eve"), vf.createURI("urn:worksAt"), vf.createURI("urn:CoffeeShop")), "b") );
        statements.add( new VisibilityStatement(
                vf.createStatement(vf.createURI("urn:Bob"), vf.createURI("urn:worksAt"), vf.createURI("urn:BurgerJoint")), "b|c") );

        // Add a statement that will generate a left result that joins with some of those right results.
        statements.add( new VisibilityStatement(
                vf.createStatement(vf.createURI("urn:Alice"), vf.createURI("urn:talksTo"), vf.createURI("urn:Bob")), "c") );

        // Make the expected results.
        final Set<VisibilityBindingSet> expected = new HashSet<>();
        MapBindingSet bs = new MapBindingSet();
        bs.addBinding("person", vf.createURI("urn:Alice"));
        bs.addBinding("employee", vf.createURI("urn:Bob"));
        bs.addBinding("business", vf.createURI("urn:TacoPlace"));
        expected.add( new VisibilityBindingSet(bs, "a&b&c") );

        bs = new MapBindingSet();
        bs.addBinding("person", vf.createURI("urn:Alice"));
        bs.addBinding("employee", vf.createURI("urn:Bob"));
        bs.addBinding("business", vf.createURI("urn:BurgerJoint"));
        expected.add( new VisibilityBindingSet(bs, "c&(b|c)") );

        // Run the test.
        KafkaTestUtil.runStreamProcessingTest(kafka, statementsTopic, resultsTopic, builder, 2000, statements, expected);
    }

    @Test
    public void newRightResult() throws Exception {
        // Enumerate some topics that will be re-used
        final String ryaInstance = UUID.randomUUID().toString();
        final UUID queryId = UUID.randomUUID();
        final String statementsTopic = KafkaTopics.statementsTopic(ryaInstance);
        final String resultsTopic = KafkaTopics.queryResultsTopic(queryId);

        // Get the StatementPatterns that will be evaluated.
        final StatementPattern leftSp = RdfTestUtil.getSp("SELECT * WHERE { ?person <urn:talksTo> ?employee }");
        final StatementPattern rightSp = RdfTestUtil.getSp("SELECT * WHERE { ?employee <urn:worksAt> ?business }");

        // Setup a topology.
        final TopologyBuilder builder = new TopologyBuilder();

        // The topic that Statements are written to is used as a source.
        builder.addSource("STATEMENTS", new StringDeserializer(), new VisibilityStatementDeserializer(), statementsTopic);

        // Add a processor that handles the first statement pattern.
        builder.addProcessor("LEFT_SP", new StatementPatternProcessorSupplier(leftSp,
                result -> ProcessorResult.make( new BinaryResult(Side.RIGHT, result) )), "STATEMENTS");

        // Add a processor that handles the second statement pattern.
        builder.addProcessor("RIGHT_SP", new StatementPatternProcessorSupplier(rightSp,
                result -> ProcessorResult.make( new BinaryResult(Side.LEFT, result) )), "STATEMENTS");

        // Add a processor that handles a natrual join over the SPs.
        builder.addProcessor("NATURAL_JOIN", new JoinProcessorSupplier(
                "NATURAL_JOIN",
                new NaturalJoin(),
                Lists.newArrayList("employee"),
                Lists.newArrayList("employee", "person", "business"),
                result -> ProcessorResult.make( new UnaryResult(result) )), "LEFT_SP", "RIGHT_SP");

        // Add a state store for the join processor.
        final StateStoreSupplier joinStoreSupplier =
                Stores.create( "NATURAL_JOIN" )
                .withStringKeys()
                .withValues(new VisibilityBindingSetSerde())
                .inMemory()
                .build();
        builder.addStateStore(joinStoreSupplier, "NATURAL_JOIN");

        // Add a processor that formats the VisibilityBindingSet for output.
        builder.addProcessor("SINK_FORMATTER", BindingSetOutputFormatter::new, "NATURAL_JOIN");

        // Add a sink that writes the data out to a new Kafka topic.
        builder.addSink("QUERY_RESULTS", resultsTopic, new StringSerializer(), new VisibilityBindingSetSerializer(), "SINK_FORMATTER");

        // Create some statements that generate a bunch of right SP results.
        final ValueFactory vf = new ValueFactoryImpl();
        final List<VisibilityStatement> statements = new ArrayList<>();
        statements.add( new VisibilityStatement(
                vf.createStatement(vf.createURI("urn:Bob"), vf.createURI("urn:worksAt"), vf.createURI("urn:TacoPlace")), "a&b") );
        statements.add( new VisibilityStatement(
                vf.createStatement(vf.createURI("urn:Charlie"), vf.createURI("urn:worksAt"), vf.createURI("urn:BurgerJoint")), "a") );
        statements.add( new VisibilityStatement(
                vf.createStatement(vf.createURI("urn:Eve"), vf.createURI("urn:worksAt"), vf.createURI("urn:CoffeeShop")), "b") );
        statements.add( new VisibilityStatement(
                vf.createStatement(vf.createURI("urn:Bob"), vf.createURI("urn:worksAt"), vf.createURI("urn:BurgerJoint")), "b|c") );

        // Add a statement that will generate a left result that joins with some of those right results.
        statements.add( new VisibilityStatement(
                vf.createStatement(vf.createURI("urn:Alice"), vf.createURI("urn:talksTo"), vf.createURI("urn:Bob")), "c") );

        // Make the expected results.
        final Set<VisibilityBindingSet> expected = new HashSet<>();
        MapBindingSet bs = new MapBindingSet();
        bs.addBinding("person", vf.createURI("urn:Alice"));
        bs.addBinding("employee", vf.createURI("urn:Bob"));
        bs.addBinding("business", vf.createURI("urn:TacoPlace"));
        expected.add( new VisibilityBindingSet(bs, "a&b&c") );

        bs = new MapBindingSet();
        bs.addBinding("person", vf.createURI("urn:Alice"));
        bs.addBinding("employee", vf.createURI("urn:Bob"));
        bs.addBinding("business", vf.createURI("urn:BurgerJoint"));
        expected.add( new VisibilityBindingSet(bs, "c&(b|c)") );

        // Run the test.
        KafkaTestUtil.runStreamProcessingTest(kafka, statementsTopic, resultsTopic, builder, 2000, statements, expected);
    }

    @Test
    public void newResultsBothSides() throws Exception {
        // Enumerate some topics that will be re-used
        final String ryaInstance = UUID.randomUUID().toString();
        final UUID queryId = UUID.randomUUID();
        final String statementsTopic = KafkaTopics.statementsTopic(ryaInstance);
        final String resultsTopic = KafkaTopics.queryResultsTopic(queryId);

        // Get the StatementPatterns that will be evaluated.
        final StatementPattern leftSp = RdfTestUtil.getSp("SELECT * WHERE { ?person <urn:talksTo> ?employee }");
        final StatementPattern rightSp = RdfTestUtil.getSp("SELECT * WHERE { ?employee <urn:worksAt> ?business }");

        // Setup a topology.
        final TopologyBuilder builder = new TopologyBuilder();

        // The topic that Statements are written to is used as a source.
        builder.addSource("STATEMENTS", new StringDeserializer(), new VisibilityStatementDeserializer(), statementsTopic);

        // Add a processor that handles the first statement pattern.
        builder.addProcessor("LEFT_SP", new StatementPatternProcessorSupplier(leftSp,
                result -> ProcessorResult.make( new BinaryResult(Side.LEFT, result) )), "STATEMENTS");

        // Add a processor that handles the second statement pattern.
        builder.addProcessor("RIGHT_SP", new StatementPatternProcessorSupplier(rightSp,
                result -> ProcessorResult.make( new BinaryResult(Side.RIGHT, result) )), "STATEMENTS");

        // Add a processor that handles a natrual join over the SPs.
        builder.addProcessor("NATURAL_JOIN", new JoinProcessorSupplier(
                "NATURAL_JOIN",
                new NaturalJoin(),
                Lists.newArrayList("employee"),
                Lists.newArrayList("employee", "person", "business"),
                result -> ProcessorResult.make( new UnaryResult(result) )), "LEFT_SP", "RIGHT_SP");

        // Add a state store for the join processor.
        final StateStoreSupplier joinStoreSupplier =
                Stores.create( "NATURAL_JOIN" )
                .withStringKeys()
                .withValues(new VisibilityBindingSetSerde())
                .inMemory()
                .build();
        builder.addStateStore(joinStoreSupplier, "NATURAL_JOIN");

        // Add a processor that formats the VisibilityBindingSet for output.
        builder.addProcessor("SINK_FORMATTER", BindingSetOutputFormatter::new, "NATURAL_JOIN");

        // Add a sink that writes the data out to a new Kafka topic.
        builder.addSink("QUERY_RESULTS", resultsTopic, new StringSerializer(), new VisibilityBindingSetSerializer(), "SINK_FORMATTER");

        // Create some statements that generate a bunch of right SP results.
        final ValueFactory vf = new ValueFactoryImpl();
        final List<VisibilityStatement> statements = new ArrayList<>();
        statements.add( new VisibilityStatement(
                vf.createStatement(vf.createURI("urn:Bob"), vf.createURI("urn:worksAt"), vf.createURI("urn:TacoPlace")), "a&b") );
        statements.add( new VisibilityStatement(
                vf.createStatement(vf.createURI("urn:Alice"), vf.createURI("urn:talksTo"), vf.createURI("urn:Bob")), "c") );
        statements.add( new VisibilityStatement(
                vf.createStatement(vf.createURI("urn:Charlie"), vf.createURI("urn:worksAt"), vf.createURI("urn:BurgerJoint")), "a") );
        statements.add( new VisibilityStatement(
                vf.createStatement(vf.createURI("urn:Eve"), vf.createURI("urn:worksAt"), vf.createURI("urn:CoffeeShop")), "b") );
        statements.add( new VisibilityStatement(
                vf.createStatement(vf.createURI("urn:Bob"), vf.createURI("urn:worksAt"), vf.createURI("urn:BurgerJoint")), "b|c") );
        statements.add( new VisibilityStatement(
                vf.createStatement(vf.createURI("urn:Bob"), vf.createURI("urn:talksTo"), vf.createURI("urn:Charlie")), "c") );

        // Make the expected results.
        final Set<VisibilityBindingSet> expected = new HashSet<>();
        MapBindingSet bs = new MapBindingSet();
        bs.addBinding("person", vf.createURI("urn:Alice"));
        bs.addBinding("employee", vf.createURI("urn:Bob"));
        bs.addBinding("business", vf.createURI("urn:TacoPlace"));
        expected.add( new VisibilityBindingSet(bs, "a&b&c") );

        bs = new MapBindingSet();
        bs.addBinding("person", vf.createURI("urn:Alice"));
        bs.addBinding("employee", vf.createURI("urn:Bob"));
        bs.addBinding("business", vf.createURI("urn:BurgerJoint"));
        expected.add( new VisibilityBindingSet(bs, "c&(b|c)") );

        bs = new MapBindingSet();
        bs.addBinding("person", vf.createURI("urn:Bob"));
        bs.addBinding("employee", vf.createURI("urn:Charlie"));
        bs.addBinding("business", vf.createURI("urn:BurgerJoint"));
        expected.add( new VisibilityBindingSet(bs, "a&c") );

        // Run the test.
        KafkaTestUtil.runStreamProcessingTest(kafka, statementsTopic, resultsTopic, builder, 2000, statements, expected);
    }

    @Test
    public void manyJoins() throws Exception {
        // Enumerate some topics that will be re-used
        final String ryaInstance = UUID.randomUUID().toString();
        final UUID queryId = UUID.randomUUID();
        final String statementsTopic = KafkaTopics.statementsTopic(ryaInstance);
        final String resultsTopic = KafkaTopics.queryResultsTopic(queryId);

        // Get the StatementPatterns that will be evaluated.
        final StatementPattern sp1 = RdfTestUtil.getSp("SELECT * WHERE { ?person <urn:talksTo> ?employee }");
        final StatementPattern sp2 = RdfTestUtil.getSp("SELECT * WHERE { ?employee <urn:worksAt> ?business }");
        final StatementPattern sp3 = RdfTestUtil.getSp("SELECT * WHERE { ?employee <urn:hourlyWage> ?wage }");

        // Setup a topology.
        final TopologyBuilder builder = new TopologyBuilder();

        // The topic that Statements are written to is used as a source.
        builder.addSource("STATEMENTS", new StringDeserializer(), new VisibilityStatementDeserializer(), statementsTopic);

        // Add a processor that handles the first statement pattern.
        builder.addProcessor("SP1", new StatementPatternProcessorSupplier(sp1,
                result -> ProcessorResult.make( new BinaryResult(Side.LEFT, result) )), "STATEMENTS");

        // Add a processor that handles the second statement pattern.
        builder.addProcessor("SP2", new StatementPatternProcessorSupplier(sp2,
                result -> ProcessorResult.make( new BinaryResult(Side.RIGHT, result) )), "STATEMENTS");

        // Add a processor that handles a natural join over SPs 1 and 2.
        builder.addProcessor("JOIN1", new JoinProcessorSupplier(
                "JOIN1",
                new NaturalJoin(),
                Lists.newArrayList("employee"),
                Lists.newArrayList("employee", "person", "business"),
                result -> ProcessorResult.make( new BinaryResult(Side.LEFT, result) )), "SP1", "SP2");

        // Add a processor that handles the third statement pattern.
        builder.addProcessor("SP3", new StatementPatternProcessorSupplier(sp3,
                result -> ProcessorResult.make( new BinaryResult(Side.RIGHT, result) )), "STATEMENTS");

        // Add a processor that handles a natural join over JOIN1 and SP3.
        builder.addProcessor("JOIN2", new JoinProcessorSupplier(
                "JOIN2",
                new NaturalJoin(),
                Lists.newArrayList("employee"),
                Lists.newArrayList("employee", "business", "wage"),
                result -> ProcessorResult.make( new UnaryResult(result) )), "JOIN1", "SP3");

        // Setup the join state suppliers.
        final StateStoreSupplier join1StoreSupplier =
                Stores.create( "JOIN1" )
                .withStringKeys()
                .withValues(new VisibilityBindingSetSerde())
                .inMemory()
                .build();
        builder.addStateStore(join1StoreSupplier, "JOIN1");

        final StateStoreSupplier join2StoreSupplier =
                Stores.create( "JOIN2" )
                .withStringKeys()
                .withValues(new VisibilityBindingSetSerde())
                .inMemory()
                .build();
        builder.addStateStore(join2StoreSupplier, "JOIN2");

        // Add a processor that formats the VisibilityBindingSet for output.
        builder.addProcessor("SINK_FORMATTER", BindingSetOutputFormatter::new, "JOIN2");

        // Add a sink that writes the data out to a new Kafka topic.
        builder.addSink("QUERY_RESULTS", resultsTopic, new StringSerializer(), new VisibilityBindingSetSerializer(), "SINK_FORMATTER");

        // Create some statements that generate a bunch of right SP results.
        final ValueFactory vf = new ValueFactoryImpl();
        final List<VisibilityStatement> statements = new ArrayList<>();
        statements.add( new VisibilityStatement(
                vf.createStatement(vf.createURI("urn:Alice"), vf.createURI("urn:talksTo"), vf.createURI("urn:Bob")), "a") );
        statements.add( new VisibilityStatement(
                vf.createStatement(vf.createURI("urn:Bob"), vf.createURI("urn:worksAt"), vf.createURI("urn:BurgerJoint")), "a") );
        statements.add( new VisibilityStatement(
                vf.createStatement(vf.createURI("urn:Bob"), vf.createURI("urn:hourlyWage"), vf.createLiteral(7.25)), "a") );

        // Make the expected results.
        final Set<VisibilityBindingSet> expected = new HashSet<>();
        final MapBindingSet bs = new MapBindingSet();
        bs.addBinding("person", vf.createURI("urn:Alice"));
        bs.addBinding("employee", vf.createURI("urn:Bob"));
        bs.addBinding("business", vf.createURI("urn:BurgerJoint"));
        bs.addBinding("wage", vf.createLiteral(7.25));
        expected.add( new VisibilityBindingSet(bs, "a") );

        // Run the test.
        KafkaTestUtil.runStreamProcessingTest(kafka, statementsTopic, resultsTopic, builder, 3000, statements, expected);
    }

    @Test
    public void leftJoin() throws Exception {
        // Enumerate some topics that will be re-used
        final String ryaInstance = UUID.randomUUID().toString();
        final UUID queryId = UUID.randomUUID();
        final String statementsTopic = KafkaTopics.statementsTopic(ryaInstance);
        final String resultsTopic = KafkaTopics.queryResultsTopic(queryId);

        // Get the StatementPatterns that will be evaluated.
        final StatementPattern requiredSp = RdfTestUtil.getSp("SELECT * WHERE { ?person <urn:talksTo> ?employee }");
        final StatementPattern optionalSp = RdfTestUtil.getSp("SELECT * WHERE { ?employee <urn:worksAt> ?business }");

        // Setup a topology.
        final TopologyBuilder builder = new TopologyBuilder();

        // The topic that Statements are written to is used as a source.
        builder.addSource("STATEMENTS", new StringDeserializer(), new VisibilityStatementDeserializer(), statementsTopic);

        // Add a processor that handles the first statement pattern.
        builder.addProcessor("REQUIRED_SP", new StatementPatternProcessorSupplier(requiredSp,
                result -> ProcessorResult.make( new BinaryResult(Side.LEFT, result) )), "STATEMENTS");

        // Add a processor that handles the second statement pattern.
        builder.addProcessor("OPTIONAL_SP", new StatementPatternProcessorSupplier(optionalSp,
                result -> ProcessorResult.make( new BinaryResult(Side.RIGHT, result) )), "STATEMENTS");

        // Add a processor that handles a natrual join over the SPs.
        builder.addProcessor("LEFT_JOIN", new JoinProcessorSupplier(
                "LEFT_JOIN",
                new LeftOuterJoin(),
                Lists.newArrayList("employee"),
                Lists.newArrayList("employee", "person", "business"),
                result -> ProcessorResult.make( new UnaryResult(result) )), "REQUIRED_SP", "OPTIONAL_SP");

        // Add a state store for the join processor.
        final StateStoreSupplier joinStoreSupplier =
                Stores.create( "LEFT_JOIN" )
                .withStringKeys()
                .withValues(new VisibilityBindingSetSerde())
                .inMemory()
                .build();
        builder.addStateStore(joinStoreSupplier, "LEFT_JOIN");

        // Add a processor that formats the VisibilityBindingSet for output.
        builder.addProcessor("SINK_FORMATTER", BindingSetOutputFormatter::new, "LEFT_JOIN");

        // Add a sink that writes the data out to a new Kafka topic.
        builder.addSink("QUERY_RESULTS", resultsTopic, new StringSerializer(), new VisibilityBindingSetSerializer(), "SINK_FORMATTER");

        // Create some statements that generate a result that includes the optional value as well as one that does not.
        final ValueFactory vf = new ValueFactoryImpl();
        final List<VisibilityStatement> statements = new ArrayList<>();
        statements.add( new VisibilityStatement(
                vf.createStatement(vf.createURI("urn:Alice"), vf.createURI("urn:talksTo"), vf.createURI("urn:Bob")), "a") );
        statements.add( new VisibilityStatement(
                vf.createStatement(vf.createURI("urn:Bob"), vf.createURI("urn:worksAt"), vf.createURI("urn:TacoPlace")), "b") );
        statements.add( new VisibilityStatement(
                vf.createStatement(vf.createURI("urn:Bob"), vf.createURI("urn:talksTo"), vf.createURI("urn:Charlie")), "c") );
        statements.add( new VisibilityStatement(
                vf.createStatement(vf.createURI("urn:David"), vf.createURI("urn:worksAt"), vf.createURI("urn:BurgerJoint")), "d") );

        // Make the expected results.
        final Set<VisibilityBindingSet> expected = new HashSet<>();
        MapBindingSet bs = new MapBindingSet();
        bs.addBinding("person", vf.createURI("urn:Alice"));
        bs.addBinding("employee", vf.createURI("urn:Bob"));
        expected.add( new VisibilityBindingSet(bs, "a") );

        bs = new MapBindingSet();
        bs.addBinding("person", vf.createURI("urn:Alice"));
        bs.addBinding("employee", vf.createURI("urn:Bob"));
        bs.addBinding("business", vf.createURI("urn:TacoPlace"));
        expected.add( new VisibilityBindingSet(bs, "a&b") );

        bs = new MapBindingSet();
        bs.addBinding("person", vf.createURI("urn:Bob"));
        bs.addBinding("employee", vf.createURI("urn:Charlie"));
        expected.add( new VisibilityBindingSet(bs, "c") );

        // Run the test.
        KafkaTestUtil.runStreamProcessingTest(kafka, statementsTopic, resultsTopic, builder, 2000, statements, expected);
    }
}