Parse and validate forwarded IP addresses.

    Args:
      forwarded_ips: list, the IP address strings to parse.

    Returns:
      list, the valid IP address strings.

def ParseForwardedIps(self, forwarded_ips):
    """Parse and validate forwarded IP addresses.

    Args:
      forwarded_ips: list, the IP address strings to parse.

    Returns:
      list, the valid IP address strings.
    """
    addresses = []
    forwarded_ips = forwarded_ips or []
    for ip in forwarded_ips:
      if ip and (IP_REGEX.match(ip) or IP_ALIAS_REGEX.match(ip)):
        addresses.append(ip[:-3] if ip.endswith('/32') else ip)
      else:
        self.logger.warning('Could not parse IP address: "%s".', ip)
    return addresses