if (specs != null) {
            ImmutableList.Builder<SpecMatcher> builder = ImmutableList.builderWithExpectedSize(specs.size());
            for (ContentSpec spec : specs) {
                builder.add(spec.toMatcher());
            }
            matchers = builder.build();
        }
        return matchers;
    }

    private static void checkNotNull(@Nullable String value, String message) {

			}
			if port.Protocol.IsUnsupported() {
				// If we need to sniff, insert two chains and the protocol detector
				chains = append(chains, tcpChain, httpChain)
				portMapper.Map[portString] = match.ToMatcher(match.NewAppProtocol(match.ProtocolMatch{
					TCP:  match.ToChain(tcpName),
					HTTP: match.ToChain(httpName),
				}))
			} else if port.Protocol.IsHTTP() {
				// Otherwise, just insert HTTP/TCP

			return nil
		}
		match := &security.Match{
			DestinationPorts:    stringToPort(op.Ports),
			NotDestinationPorts: stringToPort(op.NotPorts),
		}
		toMatches = append(toMatches, match)
	}
	fromMatches := []*security.Match{}
	for _, from := range rule.From {
		op := from.Source