How to use the kew.reject function in kew

.then(function (infoCmdOutput) {
      var items = {}
      infoCmdOutput.split('\n')
        .filter(function(str) {return str.indexOf(':') > 0})
        .map(function(str) {return str.trim().split(':')})
        .map(function(item) {items[item[0]] = item[1]})
      var serverInfo = new ServerInfo()
      try {
        serverInfo.memoryBytes = parseInt(items['used_memory'], 10)
        serverInfo.memoryRssBytes = parseInt(items['used_memory_rss'], 10)
        serverInfo.evictedKeys = parseInt(items['evicted_keys'], 10)
        serverInfo.numOfConnections = parseInt(items['connected_clients'], 10)
        // The db0 key's value is something like: 'keys=12,expires=20'
        serverInfo.numOfKeys = parseInt(items['db0'].split(',')[0].split('=')[1], 10)
      } catch (e) {
        Q.reject(new Error('Malformatted output from the "INFO" command of Redis'))
      }
      return Q.resolve(serverInfo)
    })
}

return self.logDone(timeStart);
					});
			}

			// Reset the status buffer
			self.sStatusBuffer = '';
		}
	});

	// Define the tracklist
	self.tracklist = [];

	// Start tracklist promise as rejected, so requestors do not wait for it if not immediately available.
	// This is okay because no part of Volumio requires a populated tracklist to function.
	self.tracklistReadyDeferred = null;
	self.tracklistReady = libQ.reject('Tracklist not yet populated.');

	// Attempt to load tracklist from database on disk
	// TODO make this a relative path
	self.sTracklistPath = __dirname + '/db/tracklist';
	self.loadTracklistFromDB()
		.fail(libFast.bind(self.pushError, self));



	exec("spopd -c /etc/spopd.conf", function (error, stdout, stderr) {
		if (error !== null) {
			self.commandRouter.pushConsoleMessage('The following error occurred while starting SPOPD: ' + error);
		}
		else {
			self.commandRouter.pushConsoleMessage('SpopD Daemon Started');
		}

return self.logDone(timeStart);
					});
			}

			// Reset the status buffer
			self.sStatusBuffer = '';
		}
	});

	// Define the tracklist
	self.tracklist = [];

	// Start tracklist promise as rejected, so requestors do not wait for it if not immediately available.
	// This is okay because no part of Volumio requires a populated tracklist to function.
	self.tracklistReadyDeferred = null;
	self.tracklistReady = libQ.reject('Tracklist not yet populated.');

	// Attempt to load tracklist from database on disk
	// TODO make this a relative path
	self.sTracklistPath = __dirname + '/db/tracklist';
	self.loadTracklistFromDB()
		.fail(libFast.bind(self.pushError, self));



	exec("spopd -c /etc/spopd.conf", function (error, stdout, stderr) {
		if (error !== null) {
			self.commandRouter.pushConsoleMessage('The following error occurred while starting SPOPD: ' + error);
		}
		else {
			self.commandRouter.pushConsoleMessage('SpopD Daemon Started');
		}

ControllerMpd.prototype.haltIfNewerUpdateRunning = function (data, timeCurrentThread) {
	var self = this;
	self.commandRouter.pushConsoleMessage('ControllerMpd::haltIfNewerUpdateRunning');

	if (self.timeLatestUpdate > timeCurrentThread) {
		return libQ.reject('Alert: Aborting status update - newer one detected');
	} else {
		return libQ.resolve(data);
	}
};

FakeCache.prototype._fakeFail = function (op) {
  this._failureCount -= 1
  var failure
  if (this._nextFailure) {
    if (this._nextFailure instanceof TimeoutError) this._getTimeoutCounter(op).inc()
    failure = this._nextFailure
    this._nextFailure = null
  } else {
    failure = new Error('Fake Error')
  }
  return Q.reject(failure)
}

artist: {[Sequelize.Op.eq]: uriInfo.parts[0]},
				album: {[Sequelize.Op.eq]: uriInfo.parts[1]}
			},
			order: ['disk', 'tracknumber', 'title'],
			raw: true
		});
	} else if (uriInfo.parts.length == 1) {
		promise = this.library.searchTracks({
			where: {
				artist: {[Sequelize.Op.eq]: uriInfo.parts[0]},
			},
			order: ['disk', 'tracknumber', 'title'],
			raw: true
		});
	} else {
		return libQ.reject('DBImplementation.explodeArtistsUri: empty uri');
	}
	return promise.then(function(tracks) {
		return tracks.map(self.track2mpd.bind(self));
	});

};

var promise;
		switch (uriInfo.protocol) {
			case PROTOCOL_LIBRARY:
				promise = self.handleLibraryUri(uri);
				break;
			case PROTOCOL_ARTISTS:
				promise = self.handleArtistsUri(uri);
				break;
			case PROTOCOL_ALBUMS:
				promise = self.handleAlbumsUri(uri);
				break;
			case PROTOCOL_GENRES:
				promise = self.handleGenresUri(uri);
				break;
			default:
				promise = libQ.reject('Unknown protocol: ' + uriInfo.protocol);
		}
		return promise;
	}).then(function(response) {
		response.navigation.prev.uri = previousUri || response.navigation.prev.uri || DBImplementation.getParentUri(uriInfo);

ControllerMpd.prototype.haltIfNewerUpdateRunning = function(data, timeCurrentThread) {
	var self = this;
	self.commandRouter.pushConsoleMessage('[' + Date.now() + '] ' + 'ControllerMpd::haltIfNewerUpdateRunning');

	if (self.timeLatestUpdate > timeCurrentThread) {
		return libQ.reject('Alert: Aborting status update - newer one detected');
	} else {
		return libQ.resolve(data);
	}
};

ControllerMpd.prototype.haltIfNewerUpdateRunning = function (data, timeCurrentThread) {
	var self = this;
	self.commandRouter.pushConsoleMessage('ControllerMpd::haltIfNewerUpdateRunning');

	if (self.timeLatestUpdate > timeCurrentThread) {
		return libQ.reject('Alert: Aborting status update - newer one detected');
	} else {
		return libQ.resolve(data);
	}
};

InMemoryCache.prototype.set = function (key, val, maxAgeMs, setWhenNotExist) {
  if ((maxAgeMs === undefined || maxAgeMs <= 0) && !this._maxAgeOverride) {
    return Q.reject(new Error('maxAgeMs must either be positive or overriden with a positive overrideMaxAgeMs'))
  }
  this._setInternal(key, val, maxAgeMs, setWhenNotExist)
  return Q.resolve(null)
}