public KeyboardButtonGroupInfo this[KeyboardKeyInfo button]
 {
     get
     {
         return(new KeyboardButtonGroupInfo
         {
             Group = this,
             Buttons = new[] { button }
         });
     }
 }
 public KeyboardButtonGroupInfo this[KeyboardKeyInfo button]
 {
     get
     {
         return new KeyboardButtonGroupInfo
         {
             Group = this,
             Buttons = new[] { button }
         };
     }
 }