ReturnConnectionType = getResourceOrNull(graph, URIs.ReturnConnectionType);
ReturnInConnectionType = getResourceOrNull(graph, URIs.ReturnInConnectionType);
ReturnOutConnectionType = getResourceOrNull(graph, URIs.ReturnOutConnectionType);
ReturnConnectionType = getResourceOrNull(graph, URIs.ReturnConnectionType);
ReturnInConnectionType = getResourceOrNull(graph, URIs.ReturnInConnectionType);
ReturnOutConnectionType = getResourceOrNull(graph, URIs.ReturnOutConnectionType);