def METHOD_NAME(action_dict):
    assert (len(action_dict) == 1)
    for tx_type, value in action_dict.items():
        contents = convert_json_rust_instance_to_py_object(
            value, convert_transaction_type_string_to_class(tx_type))
        contents = fix_json_fields_by_tx_type(contents, tx_type)
        action = Action()
        action.enum = tx_type[0].lower() + tx_type[1:]
        setattr(action, action.enum, contents)
        return action