code: function createExecuteSuccessResponseMessage(parentMessage, executionCount, metadata) {
    var content = {
      status: 'ok',
      execution_count: executionCount,
      payload: [],
      user_variables: {},
      user_expressions: {}
    };
  
    return newMessage(_messageNames.executeResponse, parentMessage, content, metadata);
  }
docs: Creates a success execution reply message.