def get_package_by_identifier(self, identifier):
        warnings.warn(
                "You should use get_package instead of "
                "get_package_by_identifier",
                VistrailsDeprecation,
                stacklevel=2)
        return self.get_package(identifier)
convert all document field into json type
dataset/ETHPy150Open VisTrails/VisTrails/vistrails/core/packagemanager.py/PackageManager.get_package_by_identifier--crossover with--dataset/ETHPy150Open namlook/mongokit/mongokit/document.py/Document.to_json_type