code: function constructMongoLink(dbName, prefix, servers, params, credentials) {
          if (dbName && Array.isArray(servers)) {
              var url = "mongodb://";
              if (credentials && Object.hasOwnProperty.call(credentials, 'username') && credentials.hasOwnProperty.call(credentials, 'password')) {
                  url = url.concat(credentials.username, ':', credentials.password, '@');
              }
  
              servers.forEach(function (element, index, array) {
                  url = url.concat(element.host, ':', element.port, (index === array.length - 1 ? '' : ','));
              });
  
              url = url.concat('/');
              if (prefix) url = url.concat(prefix);
              url = url.concat(dbName);
  
              if (params && 'object' === typeof params && Object.keys(params).length) {
                  url = url.concat('?');
                  for (var i = 0; i < Object.keys(params).length; i++) {
                      url = url.concat(Object.keys(params)[i], '=', params[Object.keys(params)[i]], i === Object.keys(params).length - 1 ? '' : "&");
                  }
              }
              return url;
          }
          return null;
      }
docs: constructMongoLink: is a function that takes the below param and return the URL need to by mongoskin.connect
  
  @param dbName
  @param prefix
  @param servers
  @param params
  @param credentials
  @returns {*}