Defines the value for the inputted key by setting both its default and \
        value to the inputted value.
        
        :param      key   | <str>
                    value | <variant>

def define(self, key, value):
        """
        Defines the value for the inputted key by setting both its default and \
        value to the inputted value.
        
        :param      key   | <str>
                    value | <variant>
        """
        skey = nstr(key)
        self._defaults[skey] = value
        self[skey] = value