public int getApproxSize() {
        return 1;
    }
<p>Obtain the approximate size of this message object in bytes. This enables messagebus to track the size of the
send queue in both memory usage and item count. This method returns 1 by default, and must be overridden to
enable message size tracking.</p>

@return 1
messagebus/src/main/java/com/yahoo/messagebus/Message.java