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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _trivialgraph_default_namer(thing, is_edge=True):
 """ Returns a "good" string for thing in printed graphs. """

    if is_edge:
        if thing.name is None or thing.name.startswith('tmp'):
            return ''
        else:
            return '/'.join([thing.name, str(len(thing))])
    elif isinstance(thing, Const):
        return str(thing.val)
    elif isinstance(thing, WireVector):
        return thing.name or '??'
    else:
        try:
            return thing.op + str(thing.op_param or '')
        except AttributeError:
            raise PyrtlError('no naming rule for "%s"' % str(thing))