Serialization with embedded context attempts to add the context to incorrect node

[ledsoft]

When serializing a graph where an embedded context is generated for an instance (let's call it A) which has a reference to a collection of further objects, JB4JSON-LD attempts to add the embedded context to the collection node, causing the following exception:

java.lang.UnsupportedOperationException: Prepending items is not supported by this composite node.

	at cz.cvut.kbss.jsonld.serialization.model.CompositeNode.prependItem(CompositeNode.java:45)
	at cz.cvut.kbss.jsonld.serialization.JsonLdTreeBuilder.closeObject(JsonLdTreeBuilder.java:86)
	at cz.cvut.kbss.jsonld.serialization.JsonLdTreeBuilder.closeCollection(JsonLdTreeBuilder.java:129)
	at cz.cvut.kbss.jsonld.serialization.traversal.ObjectGraphTraverser.closeCollection(ObjectGraphTraverser.java:221)
	at cz.cvut.kbss.jsonld.serialization.traversal.ObjectGraphTraverser.traverseCollection(ObjectGraphTraverser.java:78)
	at cz.cvut.kbss.jsonld.serialization.traversal.ObjectGraphTraverser.traverse(ObjectGraphTraverser.java:64)
	at cz.cvut.kbss.jsonld.serialization.serializer.compact.ObjectPropertyValueSerializer.serialize(ObjectPropertyValueSerializer.java:40)
	at cz.cvut.kbss.jsonld.serialization.serializer.context.ContextBuildingObjectPropertyValueSerializer.serialize(ContextBuildingObjectPropertyValueSerializer.java:19)
	at cz.cvut.kbss.jsonld.serialization.JsonLdTreeBuilder.visitAttribute(JsonLdTreeBuilder.java:110)
	at cz.cvut.kbss.jsonld.serialization.traversal.ObjectGraphTraverser.visitAttribute(ObjectGraphTraverser.java:213)
	at cz.cvut.kbss.jsonld.serialization.traversal.ObjectGraphTraverser.serializeFields(ObjectGraphTraverser.java:116)
	at cz.cvut.kbss.jsonld.serialization.traversal.ObjectGraphTraverser.traverseSingular(ObjectGraphTraverser.java:94)
	at cz.cvut.kbss.jsonld.serialization.traversal.ObjectGraphTraverser.traverse(ObjectGraphTraverser.java:66)
	at cz.cvut.kbss.jsonld.serialization.serializer.compact.ObjectPropertyValueSerializer.serialize(ObjectPropertyValueSerializer.java:40)
	at cz.cvut.kbss.jsonld.serialization.serializer.context.ContextBuildingObjectPropertyValueSerializer.serialize(ContextBuildingObjectPropertyValueSerializer.java:19)
	at cz.cvut.kbss.jsonld.serialization.JsonLdTreeBuilder.visitAttribute(JsonLdTreeBuilder.java:110)
	at cz.cvut.kbss.jsonld.serialization.traversal.ObjectGraphTraverser.visitAttribute(ObjectGraphTraverser.java:213)
	at cz.cvut.kbss.jsonld.serialization.traversal.ObjectGraphTraverser.serializeFields(ObjectGraphTraverser.java:116)
	at cz.cvut.kbss.jsonld.serialization.traversal.ObjectGraphTraverser.traverseSingular(ObjectGraphTraverser.java:94)
	at cz.cvut.kbss.jsonld.serialization.traversal.ObjectGraphTraverser.traverse(ObjectGraphTraverser.java:66)
	at cz.cvut.kbss.jsonld.serialization.traversal.ObjectGraphTraverser.traverse(ObjectGraphTraverser.java:57)
	at cz.cvut.kbss.jsonld.serialization.ContextBuildingJsonLdSerializer.buildJsonTree(ContextBuildingJsonLdSerializer.java:82)
	at cz.cvut.kbss.jsonld.serialization.JsonLdSerializer.serialize(JsonLdSerializer.java:79)