r"""
        Returns a generator of all distinct keys in the `Properties` object and
        its `defaults` (and its `defaults`\ ’s `defaults`, etc.) in unspecified
        order

        :rtype: generator of text strings

def propertyNames(self):
        r"""
        Returns a generator of all distinct keys in the `Properties` object and
        its `defaults` (and its `defaults`\ ’s `defaults`, etc.) in unspecified
        order

        :rtype: generator of text strings
        """
        for k in self.data:
            yield k
        if self.defaults is not None:
            for k in self.defaults.propertyNames():
                if k not in self.data:
                    yield k