Java: createcontentxml in mail notification classes

incognita

I'm trying to customize the mail notification classes to meet certain requirements. However I'm unclear as to some parts of the createContentXml method used.

In the default code given, the job element is created using the following statement:
Element jobElement = mailContentRoot.addElement("Job");

The taskelement however is coded as follows:
Element currentTaskElement = currentTask.emit(jobElement, EmittableUtils.EMIT_ALL_RECURSIVELY_OPTIONS);

I was unable to understand what the purpose of this emit function is, and in what cases do i use the emit function?

In the event that i want to add further elements such as DueDate etc, would it be sufficient to just use the addElement method?