@Beta
    public boolean getCreateIfNonExistent() {
        deserialize();
        return put.getCreateIfNonExistent();
    }
Returns the raw serialized buffer. This buffer is stored as the message is received from accross the network, and
deserialized from as soon as a member is requested. This method will return null if the buffer has been decoded.

@return the buffer containing the serialized data for this message, or null
documentapi/src/main/java/com/yahoo/documentapi/messagebus/protocol/PutDocumentMessage.java