docs: function(params, callback) {
          /**
           * Callback for QB.users.get(params, callback)
           * @callback getUsersCallback
           * @param {object} error - The error object
           * @param {object} response - The user object or object with Array of users
           */
          var url;
  
          if (typeof params === 'number') {
              url = params;
              params = {};
          } else {
              if (params.login) {
                  url = 'by_login';
              } else if (params.full_name) {
                  url = 'by_full_name';
              } else if (params.facebook_id) {
                  url = 'by_facebook_id';
              } else if (params.twitter_id) {
                  url = 'by_twitter_id';
              } else if (params.phone) {
                  url = 'phone';
              } else if (params.email) {
                  url = 'by_email';
              } else if (params.tags) {
                  url = 'by_tags';
              } else if (params.external) {
                  url = 'external/' + params.external;
                  params = {};
              }
          }
  
          this.service.ajax({url: Utils.getUrl(config.urls.users, url), data: params},
              function(err, res) {
                  if (err) {
                      callback(err, null);
                  } else {
                      callback(null, res.user || res);
                  }
              });
      }