public static void clearMessageRPId() {
    messageId.set(VOID_RPID);
    // messageId.remove(); change to use remove when we drop 1.4 support
  }
Used by messages to store the id for the current message into a thread local. This allows the
comms layer to still send replies even when it can't deserialize a message.
geode-core/src/main/java/org/apache/geode/distributed/internal/ReplyProcessor21.java