code: public ChatMessage createTempMessage() {
          return ChatMessage.builder()
                  .setMessageId(tempId)
                  .setSentEventId(-1L) // temporary value, will be replaced by persistence controller
                  .setConversationId(conversationId)
                  .setSentBy(sender)
                  .setFromWhom(new Sender(sender, sender))
                  .setSentOn(System.currentTimeMillis())
                  .setParts(getAllParts())
                  .setMetadata(originalMessage.getMetadata())
                  .build();
      }
docs: Create a temporary message to be displayed while the message is being send. to be replaced later on with a final message constructed with MessageProcessor#createFinalMessage(MessageSentResponse).
  
  @return Temporary message to be saved in persistance store.