text: namespace System
  {
      /// <summary>
      /// Extension methods for <see cref="EventHandler"/>.
      /// </summary>
      public static class AbpEventHandlerExtensions
      {
          /// <summary>
          /// Raises given event safely with given arguments.
          /// </summary>
          /// <param name="eventHandler">The event handler</param>
          /// <param name="sender">Source of the event</param>
          public static void InvokeSafely(this EventHandler eventHandler, object sender)
          {
              eventHandler.InvokeSafely(sender, EventArgs.Empty);
          }
  
          /// <summary>
          /// Raises given event safely with given arguments.
          /// </summary>
          /// <param name="eventHandler">The event handler</param>
          /// <param name="sender">Source of the event</param>
          /// <param name="e">Event argument</param>
          public static void InvokeSafely(this EventHandler eventHandler, object sender, EventArgs e)
          {
              eventHandler?.Invoke(sender, e);
          }
  
          /// <summary>
          /// Raises given event safely with given arguments.
          /// </summary>
          /// <typeparam name="TEventArgs">Type of the <see cref="EventArgs"/></typeparam>
          /// <param name="eventHandler">The event handler</param>
          /// <param name="sender">Source of the event</param>
          /// <param name="e">Event argument</param>
          public static void InvokeSafely<TEventArgs>(this EventHandler<TEventArgs> eventHandler, object sender, TEventArgs e)
              where TEventArgs : EventArgs
          {
              eventHandler?.Invoke(sender, e);
          }
      }
  }