code: def _Dhcpcd(self, interfaces, logger):
      
      for interface in interfaces:
        dhcpcd = ['/sbin/dhcpcd']
        try:
          subprocess.check_call(dhcpcd + ['-x', interface])
        except subprocess.CalledProcessError:
          # Dhcpcd not yet running for this device.
          logger.info('Dhcpcd not yet running for interface %s.', interface)
        try:
          subprocess.check_call(dhcpcd + [interface])
        except subprocess.CalledProcessError:
          # The interface is already active.
          logger.warning('Could not activate interface %s.', interface)
docs: Use dhcpcd to activate the interfaces.
  
      Args:
        interfaces: list of string, the output device names to enable.
        logger: logger object, used to write to SysLog and serial port.