def return_type(type_name, formatter=None):
def _returns(func):<EOL><INDENT>annotated(func)<EOL>func.metadata.typed_returnvalue(type_name, formatter)<EOL>return func<EOL><DEDENT>return _returns<EOL>
Specify that this function returns a typed value.

    Args:
        type_name (str): A type name known to the global typedargs type system
        formatter (str): An optional name of a formatting function specified
            for the type given in type_name.