def __init__(self, tk):
self._tk = tk<EOL>self._tk_defaults = {}<EOL>for key in self.tk.keys():<EOL><INDENT>self._tk_defaults[key] = self.tk[key]<EOL><DEDENT>
Base class for all components in guizero.

:param tk:
    Top level widget instance of Tkinter which usually is the main window of the application

:return:
    None.