public int nabtoRpcSetDefaultInterface(IntPtr session, string interfaceDefinition, out string errorMessage) { IntPtr nativeResult; var status = Win32NativeMethods.nabtoRpcSetDefaultInterface(session, interfaceDefinition, out nativeResult); if (status == NABTO_FAILED_WITH_JSON_MESSAGE) { errorMessage = MoveString(nativeResult); } else { errorMessage = null; } return(status); }