code: function (event, ce) {
              var self = this, _ksGroups = event._ksGroups;    // handler's group does not match specified groups (at fire step)
              // handler's group does not match specified groups (at fire step)
              if (_ksGroups && (!self.groups || !self.groups.match(_ksGroups))) {
                  return undef;
              }
              return self.notifyInternal(event, ce);
          }
docs: run current observer's user-defined function
  @param event
  @param ce