Request for Feedback on Spring Data Graph Template API

Neo4j Template API

public interface Neo4jOperations {
    <T> T doInTransaction(GraphTransactionCallback<T> callback);

    <T> T execute(GraphCallback<T> callback);

    Node getReferenceNode();

    Node getNode(long id);

    Node createNode(Property... props);

    Relationship getRelationship(long id);

    Relationship createRelationship(Node startNode, Node endNode, RelationshipType type, Property... props);

    void index(PropertyContainer primitive, String indexName, String field, Object value);

    void index(PropertyContainer primitive, String field, Object value);

    <T> Iterable<T> queryNodes(String indexName, Object queryOrQueryObject, PathMapper<T> pathMapper);

    <T> Iterable<T> retrieveNodes(String indexName, String field, String value, PathMapper<T> pathMapper);

    <T> Iterable<T> queryRelationships(String indexName, Object queryOrQueryObject, PathMapper<T> pathMapper);

    <T> Iterable<T> retrieveRelationships(String indexName, String field, String value, PathMapper<T> pathMapper);

    <T> Iterable<T> traverse(Node startNode, TraversalDescription traversal, PathMapper<T> pathMapper);

    <T> Iterable<T> traverseDirectRelationships(Node startNode, RelationshipType type, Direction direction, PathMapper<T> pathMapper);

    <T> Iterable<T> traverseDirectRelationships(Node startNode, PathMapper<T> pathMapper, RelationshipType... type);

    <T> Iterable<T> traverseDirectRelationships(Node startNode, PathMapper<T> pathMapper);

}

// Usage:

   @Test
    public void testDoInTransaction() throws Exception {
        Node refNode = template.doInTransaction(new GraphTransactionCallback<Node>() {
            @Override
            public Node doWithGraph(Status status, GraphDatabaseService graph) throws Exception {
                Node referenceNode = graph.getReferenceNode();
                referenceNode.setProperty("test", "testDoInTransaction");
                return referenceNode;
            }
        });
        assertEquals("same reference node",referenceNode,refNode);
        assertTestPropertySet(referenceNode, "testDoInTransaction");
    }

    @Test
    public void testCreateNodeWithProperties() throws Exception {
        Node node=template.createNode(_("test", "testCreateNodeWithProperties"));
        assertTestPropertySet(node, "testCreateNodeWithProperties");
    }

Iterable<String> result=template.traverse(startNode, Traversal.description().filter(returnAllButStartNode()).relationships(HAS),
                new PathMapper<String>() {
                    @Override
                    public String mapPath(Path path) {
                        return (String) path.endNode().getProperty("name", "");
                    }
                });