'Return a hashable tuple of properties.
Not intended to be human readable, but useful for backends who
want to cache derived information about text (e.g., layouts) and
need to know if the text has changed.'

def get_prop_tup(self, renderer=None):

    props = [p for p in Text.get_prop_tup(self, renderer=renderer)]
    props.extend([self._x, self._y, self._dashlength, self._dashdirection, self._dashrotation, self._dashpad, self._dashpush])
    return tuple(props)
