def show_onoff(b):
if not isinstance(b, bool):<EOL><INDENT>return "<STR_LIT>"<EOL><DEDENT>if b:<EOL><INDENT>return "<STR_LIT>"<EOL><DEDENT>return "<STR_LIT>"<EOL>
Return 'on' for True and 'off' for False, and ?? for anything
    else.