def _geo_field(self, field_name=None):
        if field_name is None:
            # Incrementing until the first geographic field is found.
            for field in self.model._meta.fields:
                if isinstance(field, GeometryField):
                    return field
            return False
        else:
            # Otherwise, check by the given field name -- which may be
            # a lookup to a _related_ geographic field.
            return GISLookup._check_geo_field(self.model._meta, field_name)
This method sets and unsets the current font to be underlined
dataset/ETHPy150Open django/django/django/contrib/gis/db/models/query.py/GeoQuerySet._geo_field--crossover with--dataset/ETHPy150Open sightmachine/SimpleCV/SimpleCV/DrawingLayer.py/DrawingLayer.setFontUnderline