code: function setStatus(err) {
      var code = constants.status.UNKNOWN;
      var details = 'Unknown Error';
      var metadata = new Metadata();
      if (err.hasOwnProperty('message')) {
        details = err.message;
      }
      if (err.hasOwnProperty('code')) {
        code = err.code;
        if (err.hasOwnProperty('details')) {
          details = err.details;
        }
      }
      if (err.hasOwnProperty('metadata')) {
        metadata = err.metadata;
      }
      stream.status = {code: code, details: details, metadata: metadata};
    }
docs: Set the pending status to a given error status. If the error does not have
  code or details properties, the code will be set to grpc.status.UNKNOWN
  and the details will be set to 'Unknown Error'.
  @param {Error} err The error object