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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def to_python(self, value):
 """Returns a GEOS Polygon from bounding box values."""

        value = super(BoundingBoxField, self).to_python(value)
        try:
            bbox = gdal.OGRGeometry.from_bbox(value).geos
        except (ValueError, AttributeError):
            return []
        bbox.srid = self.srid
        return bbox