docs: def postgis_type(self):
          """
          Get the type of the geometry in PostGIS format, including additional
          dimensions and SRID if they exist.
          """
          dimz = "Z" if self.dimz else ""
          dimm = "M" if self.dimm else ""
          if self.srid:
              return "geometry({}{}{},{})".format(self.type, dimz, dimm, self.srid)
          else:
              return "geometry({}{}{})".format(self.type, dimz, dimm)