private static String[] split(Object obj) {
            if (obj == null) {
                return null;
            }
            return obj.toString().split(":", 2);
        }
`remote.toString()`, or `local.toString()` are expected to be like `/127.0.0.1:12345`
@param remote remote address
@param local local address
@param socketId socket id
@return entry of socket index
collector/src/main/java/com/navercorp/pinpoint/collector/grpc/channelz/service/ChannelzSocketLookup.java