code: function(publicKey, expandGroups, callback) {
          var qs = '';
          if (!callback && typeof expandGroups === 'function') {
              callback = expandGroups;
          } else if (expandGroups) {
              qs = '?expandGroups=1';
          }
  
          request.get(
              this.getResourceUrl({ path: '/keys/' + publicKey + '/access' + qs, user: null }),
              function onAccessControlRulesResponse(err, res, body) {
                  callback(err, body, res);
              }
          );
          return this;
      }
docs: Get a list of access control rules for a given public key
  
  @param {String} publicKey
  @param {Boolean} expandGroups
  @param {Function} callback
  @return {ImboClient}