withMnemonic 
  Creates a new GtkCheckButton with the given text and a mnemonic.
Return
a new GtkCheckButton
Parameters
label
The text of the button, with an underscore in front of the mnemonic character
Creates a new GtkCheckButton with the given text and a mnemonic.
a new GtkCheckButton
The text of the button, with an underscore in front of the mnemonic character