docs: function(scope, element, isolate, unregisterCallback) {
          scope.$emit('registerChild', isolate);
  
          element.one('$destroy', function() {
            if ('removeMethod' in isolate) {
              isolate.removeMethod(isolate.id);
            }
  
            if(isolate && isolate.hide) { isolate.hide(); }
  
            // Invoke the callback, if provided
            if(unregisterCallback) unregisterCallback();
          });
        }