Registers the wrapped method as a JSON converter for the provided types.

    NOTE: custom converters are always globally applied

def json_convert(*kinds):
    """Registers the wrapped method as a JSON converter for the provided types.

    NOTE: custom converters are always globally applied
    """
    def register_json_converter(function):
        for kind in kinds:
            json_converters[kind] = function
        return function
    return register_json_converter