Generalized getter for the boolean properties on the ``<a:tblPr>``
        child element. Defaults to False if *propname* attribute is missing
        or ``<a:tblPr>`` element itself is not present.

def _get_boolean_property(self, propname):
        """
        Generalized getter for the boolean properties on the ``<a:tblPr>``
        child element. Defaults to False if *propname* attribute is missing
        or ``<a:tblPr>`` element itself is not present.
        """
        tblPr = self.tblPr
        if tblPr is None:
            return False
        propval = getattr(tblPr, propname)
        return {
            True:  True,
            False: False,
            None:  False
        }[propval]