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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 attr_list(label=None, kwargs=None, attributes=None):
 """Return assembled DOT attribute list string. Sorts ``kwargs`` and ``attributes`` if they are plain dicts (to avoid unpredictable order from hash randomization in Python 3 versions). '' ' [label="spam spam" eggs=eggs ham="ham ham"]' ' [eggs=""]' """

    content = a_list(label, kwargs, attributes)
    if not content:
        return ''
    return ' [%s]' % content