code: function(messageContent) {
                  /**
                   * + MessageChangeStateVO       {object}
                   *    - messageId               {long}
                   *    - participantId           {long}
                   *    - conversationId          {long}
                   */
  
                  var MessageChangeState = {
                      messageId: messageContent.messageId,
                      senderId: messageContent.participantId,
                      threadId: messageContent.conversationId
                  };
  
                  return MessageChangeState;
              }
docs: *****************************************************
  P R I V A T E   M E T H O D S            *
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