/*
 * 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.


 getCoveredAnnotations() contains code adapted from the UIMA Subiterator class.
 */
package org.apache.uima.fit.util;

import static java.util.Arrays.asList;
import static org.apache.uima.fit.factory.TypeSystemDescriptionFactory.createTypeSystemDescription;
import static org.apache.uima.fit.util.JCasUtil.contains;
import static org.apache.uima.fit.util.JCasUtil.exists;
import static org.apache.uima.fit.util.JCasUtil.getAnnotationType;
import static org.apache.uima.fit.util.JCasUtil.getType;
import static org.apache.uima.fit.util.JCasUtil.getView;
import static org.apache.uima.fit.util.JCasUtil.indexCovered;
import static org.apache.uima.fit.util.JCasUtil.indexCovering;
import static org.apache.uima.fit.util.JCasUtil.select;
import static org.apache.uima.fit.util.JCasUtil.selectBetween;
import static org.apache.uima.fit.util.JCasUtil.selectCovered;
import static org.apache.uima.fit.util.JCasUtil.selectCovering;
import static org.apache.uima.fit.util.JCasUtil.selectFollowing;
import static org.apache.uima.fit.util.JCasUtil.selectPreceding;
import static org.apache.uima.fit.util.JCasUtil.selectSingle;
import static org.apache.uima.fit.util.JCasUtil.selectSingleRelative;
import static org.apache.uima.fit.util.JCasUtil.toText;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Random;

import org.apache.uima.UIMAException;
import org.apache.uima.cas.CAS;
import org.apache.uima.cas.FeatureStructure;
import org.apache.uima.cas.Type;
import org.apache.uima.fit.ComponentTestBase;
import org.apache.uima.fit.type.AnalyzedText;
import org.apache.uima.fit.type.Sentence;
import org.apache.uima.fit.type.Token;
import org.apache.uima.jcas.JCas;
import org.apache.uima.jcas.cas.EmptyFSList;
import org.apache.uima.jcas.cas.FSArray;
import org.apache.uima.jcas.cas.NonEmptyFSList;
import org.apache.uima.jcas.cas.TOP;
import org.apache.uima.jcas.tcas.Annotation;
import org.apache.uima.util.CasCreationUtils;
import org.junit.Test;

/**
 * Test cases for {@link JCasUtil}.
 * 
 */
public class JCasUtilTest extends ComponentTestBase {
  /**
   * Test Tokens (Stems + Lemmas) overlapping with each other.
   */
  @Test
  public void testSelectCoveredOverlapping() {
    add(jCas, 3, 16);
    add(jCas, 37, 61);
    add(jCas, 49, 75);
    add(jCas, 54, 58);
    add(jCas, 66, 84);

    for (Token t : select(jCas, Token.class)) {
      // The naive approach is assumed to be correct
      List<Sentence> stem1 = selectCovered(jCas, Sentence.class, t.getBegin(), t.getEnd());
      List<Sentence> stem2 = selectCovered(jCas, Sentence.class, t);
      check(jCas, t, stem1, stem2);
    }
  }

  /**
   * Test what happens if there is actually nothing overlapping with the Token.
   */
  @Test
  public void testSelectCoveredNoOverlap() {
    new Sentence(jCas, 3, 31).addToIndexes();
    new Sentence(jCas, 21, 21).addToIndexes();
    new Sentence(jCas, 24, 44).addToIndexes();
    new Sentence(jCas, 30, 45).addToIndexes();
    new Sentence(jCas, 32, 43).addToIndexes();
    new Sentence(jCas, 47, 61).addToIndexes();
    new Sentence(jCas, 48, 77).addToIndexes();
    new Sentence(jCas, 65, 82).addToIndexes();
    new Sentence(jCas, 68, 80).addToIndexes();
    new Sentence(jCas, 72, 65).addToIndexes();

    new Token(jCas, 73, 96).addToIndexes();

    for (Token t : select(jCas, Token.class)) {
      // The naive approach is assumed to be correct
      List<Sentence> stem1 = selectCovered(jCas, Sentence.class, t.getBegin(), t.getEnd());
      List<Sentence> stem2 = selectCovered(jCas, Sentence.class, t);
      check(jCas, t, stem1, stem2);
    }
  }

  @Test
  public void testSelectCoverRandom() throws Exception {
    final int ITERATIONS = 10;

    for (int i = 0; i < ITERATIONS; i++) {
      CAS cas = jCas.getCas();
      initRandomCas(cas, 10 * i);

      JCas jcas = cas.getJCas();
      long timeNaive = 0;
      long timeOptimized = 0;
      for (Token t : select(jcas, Token.class)) {
        long ti = System.currentTimeMillis();
        // The naive approach is assumed to be correct
        List<Sentence> stem1 = selectCovered(jcas, Sentence.class, t.getBegin(), t.getEnd());
        timeNaive += System.currentTimeMillis() - ti;

        ti = System.currentTimeMillis();
        List<Sentence> stem2 = selectCovered(jcas, Sentence.class, t);
        timeOptimized += System.currentTimeMillis() - ti;

        Collection<Sentence> stem3 = indexCovered(jcas, Token.class, Sentence.class).get(t);

        check(jcas, t, stem1, stem2);
        check(jcas, t, stem1, stem3);
      }
//      System.out.format("Speed up factor %.2f [naive:%d optimized:%d diff:%d]\n",
//              (double) timeNaive / (double) timeOptimized, timeNaive, timeOptimized, timeNaive
//                      - timeOptimized);
    }
  }

  /**
   * Test what happens if there is actually nothing overlapping with the Token.
   */
  @Test
  public void testSelectBetweenInclusion() {
    Token t1 = new Token(jCas, 45, 57);
    t1.addToIndexes();
    Token t2 = new Token(jCas, 52, 52);
    t2.addToIndexes();

    new Sentence(jCas, 52, 52).addToIndexes();

    List<Sentence> stem1 = selectBetween(jCas, Sentence.class, t1, t2);
    assertTrue(stem1.isEmpty());
  }

  @Test
  public void testSelectBetweenRandom() throws Exception {
    final int ITERATIONS = 10;

    Random rnd = new Random();

    for (int i = 1; i <= ITERATIONS; i++) {
      CAS cas = jCas.getCas();
      initRandomCas(cas, 10 * i);

      JCas jcas = cas.getJCas();
      List<Token> tokens = new ArrayList<Token>(select(jcas, Token.class));

//      long timeNaive = 0;
//      long timeOptimized = 0;
      for (int j = 0; j < ITERATIONS; j++) {
        Token t1 = tokens.get(rnd.nextInt(tokens.size()));
        Token t2 = tokens.get(rnd.nextInt(tokens.size()));

        int left = Math.min(t1.getEnd(), t2.getEnd());
        int right = Math.max(t1.getBegin(), t2.getBegin());

//        long ti;
        List<Sentence> reference;
        if ((t1.getBegin() < t2.getBegin() && t2.getBegin() < t1.getEnd())
                || (t1.getBegin() < t2.getEnd() && t2.getEnd() < t1.getEnd())
                || (t2.getBegin() < t1.getBegin() && t1.getBegin() < t2.getEnd())
                || (t2.getBegin() < t1.getEnd() && t1.getEnd() < t2.getEnd())) {
          // If the boundary annotations overlap, the result must be empty
//          ti = System.currentTimeMillis();
          reference = new ArrayList<Sentence>();
//          timeNaive += System.currentTimeMillis() - ti;
        } else {
//          ti = System.currentTimeMillis();
          reference = selectCovered(jcas, Sentence.class, left, right);
//          timeNaive += System.currentTimeMillis() - ti;
        }

//        ti = System.currentTimeMillis();
        List<Sentence> actual = selectBetween(Sentence.class, t1, t2);
//        timeOptimized += System.currentTimeMillis() - ti;

        assertEquals("Naive: Searching between " + t1 + " and " + t2, reference, actual);
      }

//      System.out.format("Speed up factor %.2f [naive:%d optimized:%d diff:%d]\n",
//              (double) timeNaive / (double) timeOptimized, timeNaive, timeOptimized, timeNaive
//                      - timeOptimized);
    }
  }

  /**
   * Test Tokens (Stems + Lemmas) overlapping with each other.
   */
  @Test
  public void testSelectCoveringOverlapping() {
    add(jCas, 3, 16);
    add(jCas, 37, 61);
    add(jCas, 49, 75);
    add(jCas, 54, 58);
    add(jCas, 66, 84);

    assertEquals(0, selectCovering(jCas, Token.class, 36, 52).size());
    assertEquals(1, selectCovering(jCas, Token.class, 37, 52).size());
    assertEquals(2, selectCovering(jCas, Token.class, 49, 52).size());
  }

  private void initRandomCas(CAS cas, int size) {
    Random rnd = new Random();
    List<Type> types = new ArrayList<Type>();
    types.add(cas.getTypeSystem().getType(Token.class.getName()));
    types.add(cas.getTypeSystem().getType(Sentence.class.getName()));

    // Shuffle the types
    for (int n = 0; n < 10; n++) {
      Type t = types.remove(rnd.nextInt(types.size()));
      types.add(t);
    }

    // Randomly generate annotations
    for (int n = 0; n < size; n++) {
      for (Type t : types) {
        int begin = rnd.nextInt(100);
        int end = begin + rnd.nextInt(30);
        cas.addFsToIndexes(cas.createAnnotation(t, begin, end));
      }
    }
  }

  @SuppressWarnings("unused")
  private void print(Collection<? extends Annotation> annos) {
    for (Annotation a : annos) {
      System.out.println(a.getClass().getSimpleName() + " " + a.getBegin() + " " + a.getEnd());
    }
  }

  private Token add(JCas jcas, int begin, int end) {
    Token t = new Token(jcas, begin, end);
    t.addToIndexes();
    new Sentence(jcas, begin, end).addToIndexes();
    return t;
  }

  private void check(JCas jcas, Token t, Collection<? extends Annotation> a1,
          Collection<? extends Annotation> a2) {
    // List<Annotation> annos = new ArrayList<Annotation>();
    // FSIterator fs = jcas.getAnnotationIndex().iterator();
    // while (fs.hasNext()) {
    // annos.add((Annotation) fs.next());
    // }
    //
    // System.out.println("--- Index");
    // print(annos);
    // System.out.println("--- Container");
    // print(Collections.singleton(t));
    // System.out.println("--- Naive");
    // print(a1);
    // System.out.println("--- Optimized");
    // print(a2);
    assertEquals("Container: [" + t.getBegin() + ".." + t.getEnd() + "]", a1, a2);
  }

  @Test
  public void testIterator() throws Exception {
    String text = "Rot wood cheeses dew?";
    tokenBuilder.buildTokens(jCas, text);

    assertEquals(asList("Rot", "wood", "cheeses", "dew?"),
            toText(JCasUtil.select(jCas, Token.class)));
  }

  @Test
  public void testSelectByIndex() {
    String text = "Rot wood cheeses dew?";
    tokenBuilder.buildTokens(jCas, text);

    assertEquals("dew?", JCasUtil.selectByIndex(jCas, Token.class, -1).getCoveredText());
    assertEquals("dew?", JCasUtil.selectByIndex(jCas, Token.class, 3).getCoveredText());
    assertEquals("Rot", JCasUtil.selectByIndex(jCas, Token.class, 0).getCoveredText());
    assertEquals("Rot", JCasUtil.selectByIndex(jCas, Token.class, -4).getCoveredText());
    assertNull(JCasUtil.selectByIndex(jCas, Token.class, -5));
    assertNull(JCasUtil.selectByIndex(jCas, Token.class, 4));
  }

  @SuppressWarnings({ "rawtypes", "unchecked" })
  @Test
  public void testSelectOnArrays() throws Exception {
    String text = "Rot wood cheeses dew?";
    tokenBuilder.buildTokens(jCas, text);

    Collection<TOP> allFS = select(jCas, TOP.class);
    FSArray allFSArray = new FSArray(jCas, allFS.size());
    int i = 0;
    for (FeatureStructure fs : allFS) {
      allFSArray.set(i, fs);
      i++;
    }

    // Print what is expected
//    for (FeatureStructure fs : allFS) {
//      System.out.println("Type: " + fs.getType().getName() + "]");
//    }
//    System.out.println("Tokens: [" + toText(select(jCas, Token.class)) + "]");

    // Document Annotation, one sentence and 4 tokens.
    assertEquals(6, allFS.size());

    assertEquals(toText(select(jCas, Token.class)), toText(select(allFSArray, Token.class)));

    assertEquals(toText((Iterable) select(jCas, Token.class)),
            toText((Iterable) select(allFSArray, Token.class)));
  }

  @SuppressWarnings({ "rawtypes", "unchecked" })
  @Test
  public void testSelectOnLists() throws Exception {
    String text = "Rot wood cheeses dew?";
    tokenBuilder.buildTokens(jCas, text);

    Collection<TOP> allFS = select(jCas, TOP.class);

    // Building a list... OMG!
    NonEmptyFSList allFSList = new NonEmptyFSList(jCas);
    NonEmptyFSList head = allFSList;
    Iterator<TOP> i = allFS.iterator();
    while (i.hasNext()) {
      head.setHead(i.next());
      if (i.hasNext()) {
        head.setTail(new NonEmptyFSList(jCas));
        head = (NonEmptyFSList) head.getTail();
      } else {
        head.setTail(new EmptyFSList(jCas));
      }
    }

    // Print what is expected
//    for (FeatureStructure fs : allFS) {
//      System.out.println("Type: " + fs.getType().getName() + "]");
//    }
//    System.out.println("Tokens: [" + toText(select(jCas, Token.class)) + "]");

    // Document Annotation, one sentence and 4 tokens.
    assertEquals(6, allFS.size());

    assertEquals(toText(select(jCas, Token.class)), toText(select(allFSList, Token.class)));

    assertEquals(toText((Iterable) select(jCas, Token.class)),
            toText((Iterable) select(allFSList, Token.class)));
  }

  @Test
  public void testToText() {
    String text = "Rot wood cheeses dew?";
    tokenBuilder.buildTokens(jCas, text);
    assertEquals(asList(text.split(" ")), toText(select(jCas, Token.class)));
  }

  @Test
  public void testSelectSingleRelative() {
    String text = "one two three";
    tokenBuilder.buildTokens(jCas, text);
    List<Token> token = new ArrayList<Token>(select(jCas, Token.class));

    Token preceding = selectSingleRelative(jCas, Token.class, token.get(1), -1);
    assertEquals(token.get(0).getCoveredText(), preceding.getCoveredText());

    Token following = selectSingleRelative(jCas, Token.class, token.get(1), 1);
    assertEquals(token.get(2).getCoveredText(), following.getCoveredText());
  }

  @Test
  public void testSelectFollowingPreceding() {
    String text = "one two three";
    tokenBuilder.buildTokens(jCas, text);
    List<Token> token = new ArrayList<Token>(select(jCas, Token.class));

    assertEquals(token.get(0).getCoveredText(), selectPreceding(jCas, Token.class, token.get(1), 1)
            .get(0).getCoveredText());
    assertEquals(token.get(2).getCoveredText(), selectFollowing(jCas, Token.class, token.get(1), 1)
            .get(0).getCoveredText());
  }

  @Test
  public void testSelectFollowingPrecedingBuiltinTypes() {
    this.jCas.setDocumentText("A B C");
    // remove the DocumentAnnotation
    for (Annotation ann : JCasUtil.select(jCas, Annotation.class)) {
      ann.removeFromIndexes();
    }
    Annotation a = new Annotation(this.jCas, 0, 1);
    Annotation b = new Annotation(this.jCas, 2, 3);
    Annotation c = new Annotation(this.jCas, 4, 5);
    for (Annotation ann : Arrays.asList(a, b, c)) {
      ann.addToIndexes();
    }

    assertEquals(Arrays.asList(a), selectPreceding(this.jCas, Annotation.class, b, 2));
    assertEquals(Arrays.asList(a, b), selectPreceding(this.jCas, Annotation.class, c, 2));
    assertEquals(Arrays.asList(b, c), selectFollowing(this.jCas, Annotation.class, a, 2));
    assertEquals(Arrays.asList(c), selectFollowing(this.jCas, Annotation.class, b, 2));
  }

  @Test
  public void testSelectFollowingPrecedingDifferentTypes() {
    this.jCas.setDocumentText("A B C D E");
    Token a = new Token(this.jCas, 0, 1);
    Token b = new Token(this.jCas, 2, 3);
    Token c = new Token(this.jCas, 4, 5);
    Token d = new Token(this.jCas, 6, 7);
    Token e = new Token(this.jCas, 8, 9);
    for (Token token : Arrays.asList(a, b, c, d, e)) {
      token.addToIndexes();
    }
    Sentence sentence = new Sentence(this.jCas, 2, 5);
    sentence.addToIndexes();

    List<Token> preceding = selectPreceding(this.jCas, Token.class, sentence, 1);
    assertEquals(Arrays.asList("A"), JCasUtil.toText(preceding));
    assertEquals(Arrays.asList(a), preceding);
    preceding = selectPreceding(this.jCas, Token.class, sentence, 2);
    assertEquals(Arrays.asList("A"), JCasUtil.toText(preceding));
    assertEquals(Arrays.asList(a), preceding);

    List<Token> following = selectFollowing(this.jCas, Token.class, sentence, 1);
    assertEquals(Arrays.asList("D"), JCasUtil.toText(following));
    assertEquals(Arrays.asList(d), following);
    following = selectFollowing(this.jCas, Token.class, sentence, 2);
    assertEquals(Arrays.asList("D", "E"), JCasUtil.toText(following));
    assertEquals(Arrays.asList(d, e), following);
    following = selectFollowing(this.jCas, Token.class, sentence, 3);
    assertEquals(Arrays.asList("D", "E"), JCasUtil.toText(following));
    assertEquals(Arrays.asList(d, e), following);
  }

  @Test
  public void testSelectFollowingPrecedingDifferentTypesMatchingSpansReversePriorities() {
    this.jCas.setDocumentText("A B C D E");
    Sentence a = new Sentence(this.jCas, 0, 1);
    Sentence b = new Sentence(this.jCas, 2, 3);
    Sentence c = new Sentence(this.jCas, 4, 5);
    Sentence d = new Sentence(this.jCas, 6, 7);
    Sentence e = new Sentence(this.jCas, 8, 9);
    for (Sentence sentence : Arrays.asList(a, b, c, d, e)) {
      sentence.addToIndexes();
    }
    AnalyzedText text = new AnalyzedText(this.jCas, 2, 3);
    text.addToIndexes();

    List<Sentence> preceding = selectPreceding(this.jCas, Sentence.class, text, 1);
    assertEquals(Arrays.asList("A"), JCasUtil.toText(preceding));
    assertEquals(Arrays.asList(a), preceding);
    preceding = selectPreceding(this.jCas, Sentence.class, text, 2);
    assertEquals(Arrays.asList("A"), JCasUtil.toText(preceding));
    assertEquals(Arrays.asList(a), preceding);

    List<Sentence> following = selectFollowing(this.jCas, Sentence.class, text, 1);
    assertEquals(Arrays.asList("C"), JCasUtil.toText(following));
    assertEquals(Arrays.asList(c), following);
    following = selectFollowing(this.jCas, Sentence.class, text, 2);
    assertEquals(Arrays.asList("C", "D"), JCasUtil.toText(following));
    assertEquals(Arrays.asList(c, d), following);
  }

  @Test
  public void testExists() throws UIMAException {
    JCas jcas = CasCreationUtils.createCas(createTypeSystemDescription(), null, null).getJCas();

    assertFalse(exists(jcas, Token.class));

    new Token(jcas, 0, 1).addToIndexes();

    assertTrue(exists(jcas, Token.class));
  }

  @Test
  public void testSelectSingle() throws UIMAException {
    JCas jcas = CasCreationUtils.createCas(createTypeSystemDescription(), null, null).getJCas();

    try {
      selectSingle(jcas, Token.class);
      fail("Found annotation that has not yet been created");
    } catch (IllegalArgumentException e) {
      // OK
    }

    new Token(jcas, 0, 1).addToIndexes();

    selectSingle(jcas, Token.class);

    new Token(jcas, 1, 2).addToIndexes();

    try {
      selectSingle(jcas, Token.class);
      fail("selectSingle must fail if there is more than one annotation of the type");
    } catch (IllegalArgumentException e) {
      // OK
    }
  }

  @Test
  public void testSelectIsCovered() {
    String text = "Will you come home today ? \n No , tomorrow !";
    tokenBuilder.buildTokens(jCas, text);

    List<Sentence> sentences = new ArrayList<Sentence>(select(jCas, Sentence.class));
    List<Token> tokens = new ArrayList<Token>(select(jCas, Token.class));

    assertEquals(6, selectCovered(Token.class, sentences.get(0)).size());
    assertEquals(4, selectCovered(Token.class, sentences.get(1)).size());

    assertTrue(contains(jCas, sentences.get(0), Token.class));
    tokens.get(0).removeFromIndexes();
    tokens.get(1).removeFromIndexes();
    tokens.get(2).removeFromIndexes();
    tokens.get(3).removeFromIndexes();
    tokens.get(4).removeFromIndexes();
    tokens.get(5).removeFromIndexes();
    assertFalse(contains(jCas, sentences.get(0), Token.class));
  }

  @Test
  public void testGetInternalUimaType() {
    Type t = getType(jCas, Annotation.class);
    assertNotNull(t);
  }

  @Test
  public void testGetView() throws Exception {
    JCas jcas = CasCreationUtils.createCas(createTypeSystemDescription(), null, null).getJCas();

    assertNull(getView(jcas, "view1", null));
    assertNotNull(getView(jcas, "view1", true));
    assertNotNull(getView(jcas, "view1", null));
  }

  @Test(expected = IllegalArgumentException.class)
  public void testGetNonExistingView() throws Exception {
    JCas jcas = CasCreationUtils.createCas(createTypeSystemDescription(), null, null).getJCas();
    assertNull(getView(jcas, "view1", false));
  }

  @Test
  public void testGetType() {
    String text = "Rot wood cheeses dew?";
    tokenBuilder.buildTokens(jCas, text);

    assertEquals(Token.class.getName(), getType(jCas, Token.class).getName());
    assertEquals(Token.class.getName(), getAnnotationType(jCas, Token.class).getName());
    assertEquals("uima.cas.TOP", getType(jCas, TOP.class).getName());
    assertEquals("uima.tcas.Annotation", getType(jCas, Annotation.class).getName());
    assertEquals("uima.tcas.Annotation", getAnnotationType(jCas, Annotation.class).getName());
  }

  @Test(expected = IllegalArgumentException.class)
  public void testGetNonAnnotationType() {
    String text = "Rot wood cheeses dew?";
    tokenBuilder.buildTokens(jCas, text);

    getAnnotationType(jCas, TOP.class);
  }

  @Test
  public void testIndexCovering() throws Exception {
    String text = "Will you come home today ? \n No , tomorrow !";
    tokenBuilder.buildTokens(jCas, text);

    List<Sentence> sentences = new ArrayList<Sentence>(select(jCas, Sentence.class));
    List<Token> tokens = new ArrayList<Token>(select(jCas, Token.class));

    Map<Token, Collection<Sentence>> index = indexCovering(jCas, Token.class, Sentence.class);

    // Check covering annotations are found
    assertEquals(asList(sentences.get(0)), index.get(tokens.get(0)));
    assertEquals(asList(sentences.get(1)), index.get(tokens.get(tokens.size() - 1)));

    // Check sentence 0 contains first token
    assertTrue(index.get(tokens.get(0)).contains(sentences.get(0)));

    // Check sentence 0 does not contain last token.
    assertFalse(index.get(tokens.get(tokens.size() - 1)).contains(sentences.get(0)));

    // Check the first token is contained in any sentence
    assertTrue(!index.get(tokens.get(0)).isEmpty());
    // After removing the annotation the index has to be rebuilt.
    sentences.get(0).removeFromIndexes();
    index = indexCovering(jCas, Token.class, Sentence.class);
    // Check the first token is not contained in any sentence
    assertFalse(!index.get(tokens.get(0)).isEmpty());
  }
}