'Construct a Ttk Checkbutton widget with the parent master.
STANDARD OPTIONS
class, compound, cursor, image, state, style, takefocus,
text, textvariable, underline, width
WIDGET-SPECIFIC OPTIONS
command, offvalue, onvalue, variable'

def __init__(self, master=None, **kw):

    Widget.__init__(self, master, 'ttk::checkbutton', kw)
