'The initialization function for geometry fields.  Takes the following
as keyword arguments:
srid:
The spatial reference system identifier, an OGC standard.
Defaults to 4326 (WGS84).
spatial_index:
Indicates whether to create a spatial index.  Defaults to True.
Set this instead of \'db_index\' for geographic fields since index
creation is different for geometry columns.
dim:
The number of dimensions for this geometry.  Defaults to 2.
extent:
Customize the extent, in a 4-tuple of WGS 84 coordinates, for the
geometry field entry in the `USER_SDO_GEOM_METADATA` table.  Defaults
to (-180.0, -90.0, 180.0, 90.0).
tolerance:
Define the tolerance, in meters, to use for the geometry field
entry in the `USER_SDO_GEOM_METADATA` table.  Defaults to 0.05.'

def __init__(self, verbose_name=None, srid=4326, spatial_index=True, dim=2, geography=False, **kwargs):

    self.spatial_index = spatial_index
    self.srid = srid
    self.dim = dim
    kwargs['verbose_name'] = verbose_name
    self.geography = geography
    self._extent = kwargs.pop('extent', ((-180.0), (-90.0), 180.0, 90.0))
    self._tolerance = kwargs.pop('tolerance', 0.05)
    super(GeometryField, self).__init__(**kwargs)
