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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 CallDhclient( interfaces, logger, dhclient_script=None):
 """Configure the network interfaces using dhclient. Args: interfaces: list of string, the output device names to enable. logger: logger object, used to write to SysLog and serial port. dhclient_script: string, the path to a dhclient script used by dhclient. """

  logger.info('Enabling the Ethernet interfaces %s.', interfaces)

  dhclient_command = ['dhclient']

  if dhclient_script and os.path.exists(dhclient_script):
    dhclient_command += ['-sf', dhclient_script]

  try:
    subprocess.check_call(dhclient_command + ['-x'] + interfaces)
    subprocess.check_call(dhclient_command + interfaces)
  except subprocess.CalledProcessError:
    logger.warning('Could not enable interfaces %s.', interfaces)