def sink_return(func, sink, splitter=None):  
def wrap(*args, **kwargs):<EOL><INDENT>output = func(*args, **kwargs)<EOL>if splitter is None:<EOL><INDENT>to_keep, to_sink = output<EOL><DEDENT>else:<EOL><INDENT>to_keep, to_sink = splitter(*output)<EOL><DEDENT>sink(to_sink)<EOL>return to_keep<EOL><DEDENT>return wrap<EOL>
Transform a function `func` that returns tuples into a function that returns
    single values. Call a function `sink` on the unused values.