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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 _structure(msg, fp=None, level=0, include_default=False):
 """A handy debugging aid"""

    if fp is None:
        fp = sys.stdout
    tab = ' ' * (level * 4)
    print(tab + msg.get_content_type(), end='', file=fp)
    if include_default:
        print(' [%s]' % msg.get_default_type(), file=fp)
    else:
        print(file=fp)
    if msg.is_multipart():
        for subpart in msg.get_payload():
            _structure(subpart, fp, level+1, include_default)