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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 unpatch():
 """ Unpatch any previously patched modules. This operation is idempotent. """

    _PATCHED_MODULES.discard('httplib')
    setattr(httplib, PATCH_FLAG, False)
    # _send_request encapsulates putrequest, putheader[s], and endheaders
    unwrap(httplib.HTTPConnection, '_send_request')
    unwrap(httplib.HTTPConnection, 'getresponse')
    unwrap(httplib.HTTPResponse, 'read')