docs: function addEventHandlers(scope, ctrlName, handlers) {
          if (!handlers) { return; }
  
          for (var name in handlers) {
              if (handlers.hasOwnProperty(name) && handlers[name]) {
                  scope[name] = $injector.invoke(handlers[name]);
  
                  // if it is not a function, throw error b/c dev likely made a mistake
                  if (!angular.isFunction(scope[name])) {
                      throw new Error(ctrlName + ' has uiEventHandler ' + name + ' that does not return a function');
                  }
              }
          }
      }