def METHOD_NAME(self, epsg: int):
    """
    Dynamically create a new ORM class for a EPSG/SRID.
    Note: Called within registry lock.
    """
    table_name = f"spatial_{epsg}"
    attributes = {
        '__tablename__': table_name,
        '__table_args__': (
            METADATA,
            {
                "schema": SCHEMA_NAME,
                "comment": "A product or dataset type, family of related datasets."
            }
        ),
        "dataset_ref": Column(postgres.UUID(as_uuid=True), ForeignKey(Dataset.id),
                              primary_key=True,
                              nullable=False,
                              comment="The dataset being indexed")
    }
    # Add geometry column
    attributes["extent"] = Column(Geometry('MULTIPOLYGON', srid=epsg),
                                  nullable=False,
                                  comment="The extent of the dataset")
    return orm_registry.mapped(type(f'SpatialIdx{epsg}', (SpatialIndex,), attributes))