code: function morganMongoMiddleware(options = {}, connectionOptions = {}, schemaOptions = {}, morganOptions = {}) {
      const morganMongo = new MorganMongo(options, connectionOptions, schemaOptions);
      return morgan((tokens, req, res) => {
          try {
              const logEntry = morganMongo.prepareLogEntry(tokens, req, res);
              morganMongo.persistLogEntry(logEntry);
          }
          catch (e) {
              console.log(e);
          }
          return '';
      }, morganOptions);
  }
docs: /* tslint:disable:max-line-length 
  MongooseMorgan object
  @param  {object} options - represents mongo database data, requires { connectionString : '{MONGO_URL}' } parameter.
  @param  {object} connectionOptions - mongoose ConnectionOptions ({@link https://mongoosejs.com/docs/api.html#mongoose_Mongoose-connect})
  @param  {object} schemaOptions  - mongoose SchemaOptions ({@link https://mongoosejs.com/docs/api.html#schema_Schema})
  @param  {object} morganOptions  - morgan Options ({@link https://github.com/expressjs/morgan#options})
   /* tslint:enable:max-line-length