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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 GenerateLibSig(short_name):
 """Generates a library signature suitable for a user agent field. Args: short_name: The short, product-specific string name for the library. Returns: A library signature string to append to user-supplied user-agent value. """

  with _UTILITY_LOCK:
    utilities_used = ', '.join([utility for utility
                                in sorted(_utility_registry)])
    _utility_registry.Clear()

  if utilities_used:
    return ' (%s, %s, %s, %s)' % (short_name, _COMMON_LIB_SIG, _PYTHON_VERSION,
                                  utilities_used)
  else:
    return ' (%s, %s, %s)' % (short_name, _COMMON_LIB_SIG, _PYTHON_VERSION)