Retrieval of single object not possible, if other fields use the same relation type

[SebastianWendorf]

The graph has the following relations:

(:Class)-[:DECLARES]->(:Constructor)
(:Class)-[:DECLARES]->(:Method)
(:Class)-[:DECLARES]->(:Property)

In code they are modeled as:

@Relation("DECLARES")
ConstructorDeclarationDescriptor getConstructor();
void setConstructor(ConstructorDeclarationDescriptor constructor);

@Relation("DECLARES")
List<PropertyDeclarationDescriptor> getProperties();

@Relation("DECLARES")
List<MethodDeclarationDescriptor> getMethods();

The problem is, that when I call myClassDescriptor.getConstructor() to retrieve the constructor field I get:
org.neo4j.graphdb.NotFoundException: More than one relationship[DECLARES, OUTGOING] found for Node

The retrieval of the properties and methods fields work fine.

Full Stacktrace:

org.neo4j.graphdb.NotFoundException: More than one relationship[DECLARES, OUTGOING] found for Node[2532]

	at org.neo4j.kernel.impl.core.NodeEntity.getSingleRelationship(NodeEntity.java:209)
	at com.buschmais.xo.neo4j.embedded.impl.model.EmbeddedNode.getSingleRelationship(EmbeddedNode.java:62)
	at com.buschmais.xo.neo4j.embedded.impl.datastore.EmbeddedRelationManager.getSingleRelation(EmbeddedRelationManager.java:76)
	at com.buschmais.xo.neo4j.embedded.impl.datastore.EmbeddedRelationManager.getSingleRelation(EmbeddedRelationManager.java:20)
	at com.buschmais.xo.impl.EntityPropertyManager.getEntityReference(EntityPropertyManager.java:60)
	at com.buschmais.xo.impl.proxy.entity.property.EntityReferencePropertyGetMethod.invoke(EntityReferencePropertyGetMethod.java:16)
	at com.buschmais.xo.impl.proxy.AbstractProxyMethodService.invoke(AbstractProxyMethodService.java:26)
	at com.buschmais.xo.impl.proxy.InstanceInvocationHandler.invoke(InstanceInvocationHandler.java:27)
	at com.sun.proxy.$Proxy103.getConstructor(Unknown Source)