Add gis deconstruct() method (this does not make schema work)

        super(GeometryField, self).__init__(**kwargs)

    def deconstruct(self):

        name, path, args, kwargs = super(GeometryField, self).deconstruct()

        # Always include SRID for less fragility; include others if they're

        # not the default values.

        kwargs['srid'] = self.srid

        if self.dim != 2:

            kwargs['dim'] = self.dim

        if self.spatial_index != True:

            kwargs['spatial_index'] = self.spatial_index

        if self.geography != False:

            kwargs['geography'] = self.geography

        return name, path, args, kwargs

    # The following functions are used to get the units, their name, and

    # the spheroid corresponding to the SRID of the GeometryField.

    def _get_srid_info(self, connection):

        params = []

        # Check for fields that aren't actually columns (e.g. M2M)

        if sql is None:

            return None

            return None, None

        # Work out nullability

        null = field.null

        # If we were told to include a default value, do so