src/main/patches/java6.patch

diff --git a/com/github/commonsrdf/api/Graph.java b/com/github/commonsrdf/api/Graph.java
index d55fb8c..71aca8d 100644
--- a/com/github/commonsrdf/api/Graph.java
+++ b/com/github/commonsrdf/api/Graph.java
@@ -1,6 +1,6 @@
 package com.github.commonsrdf.api;
 
-import java.util.stream.Stream;
+import java.util.Iterator;
 
 /**
  * An <a href="http://www.w3.org/TR/rdf11-concepts/#section-rdf-graph"> RDF 1.1
@@ -88,15 +88,9 @@ public interface Graph {
     /**
      * Get all triples contained by the graph.<br>
      *
-     * The behaviour of the Stream is not specified if add, remove, or clear,
-     * are called on the Stream before it terminates.<br>
-     *
-     * Implementations may throw ConcurrentModificationException from Stream
-     * methods if they detect a conflict while the Stream is active.
-     *
-     * @return A {@link Stream} over all of the triples in the graph.
+     * @return A {@link Iterator} over all of the triples in the graph.
      */
-    Stream<? extends Triple> getTriples();
+    Iterator<? extends Triple> getTriples();
 
     /**
      * Get all triples contained by the graph matched with the pattern.
@@ -113,8 +107,8 @@ public interface Graph {
      *            The triple predicate (null is a wildcard)
      * @param object
      *            The triple object (null is a wildcard)
-     * @return A {@link Stream} over the matched triples.
+     * @return A {@link Iterator} over the matched triples.
      */
-    Stream<? extends Triple> getTriples(BlankNodeOrIRI subject, IRI predicate, RDFTerm object);
+    Iterator<? extends Triple> getTriples(BlankNodeOrIRI subject, IRI predicate, RDFTerm object);
 
 }
diff --git a/com/github/commonsrdf/api/Literal.java b/com/github/commonsrdf/api/Literal.java
index 30505a3..e5638f7 100644
--- a/com/github/commonsrdf/api/Literal.java
+++ b/com/github/commonsrdf/api/Literal.java
@@ -1,6 +1,6 @@
 package com.github.commonsrdf.api;
 
-import java.util.Optional;
+import com.google.common.base.Optional;
 
 /**
  * An RDF-1.1 Literal, as defined by <a href=