code: func RequestShutdown(reason string) (int, error) {
  	creason := C.CString(reason)
  	defer C.free(unsafe.Pointer(creason))
  	return errNo(C.newrelic_request_shutdown(creason))
  }
docs: /**
   * Tell the CollectorClient to shutdown and stop reporting application
   * performance data to New Relic.
   *
   * @reason reason for shutdown request
   * @return  0 on success, error code on error, else warning code
   */