def test_build_event(self):
        evt = event.build_event("evt_name", arg1="val1", arg2=None)
        assert evt.name == "evt_name"
        assert evt.args == {'arg1': "val1", 'arg2': None}
def chart_title(self):
        """Returns a title for the chart."""
        if self.field:
            return 'Top filtered results for "{0:s}"'.format(self.field)
        return 'Top results for an unknown field after filtering'