XWiki 18.4.0+, 17.10.9+

textFormat()

Indicates how the text parameter is interpreted by XWiki.widgets.Notification.
Callers can check for the presence of this method to decide whether to escape their input:

• When this method is available, the text parameter is treated as plain text and must not be escaped.
• When this method is missing (before 18.4.0RC1/17.10.9), the text parameter is interpreted as HTML and may need to be escaped.
  The returned value is always the "plain" string.

XWiki 18.9.0+

show(text, type, options)

Displays a notification and returns it, so that hide() or replace() can be called on it later. It takes the same parameters as the constructor and is equivalent to creating a new XWiki.widgets.Notification object, which displays itself, but it makes that side effect explicit where it is called. As with the constructor, the notification is not displayed when options.inactive is set.

XWiki.widgets.Notification.show('Page saved', 'done');