public int IndexOf(dhtmlxCommand command)
 {
     if (command != null)
     {
         return(_commands.IndexOf(command));
     }
     return(-1);
 }
        public void Remove(dhtmlxCommand command)
        {
            int index = this.IndexOf(command);

            if (index >= 0)
            {
                this.RemoveAt(index);
            }
        }
 public void AddAt(int index, dhtmlxCommand command)
 {
     if (command == null)
     {
         throw new ArgumentNullException("command");
     }
     if (index == -1)
     {
         _commands.Add(command);
     }
     else
     {
         _commands.Insert(index, command);
     }
 }
 public void Add(dhtmlxCommand command)
 {
     this.AddAt(-1, command);
 }