Return True if the themeable *name* is blank

        This if the *name* is not in the list of themeables
        then the lookup falls back to inheritance hierarchy
        is considered. If the none of the themeables in the
        hierary are present, ``False`` will be returned.

        Parameters
        ----------
        names : str
            Themeable, in order of most specific to most
            general.

def is_blank(self, name):
        """
        Return True if the themeable *name* is blank

        This if the *name* is not in the list of themeables
        then the lookup falls back to inheritance hierarchy
        is considered. If the none of the themeables in the
        hierary are present, ``False`` will be returned.

        Parameters
        ----------
        names : str
            Themeable, in order of most specific to most
            general.
        """
        for th in themeable._hierarchy[name]:
            with suppress(KeyError):
                return self[th].is_blank()

        return False