public static <PS, SEG, S> UndoManager<List<RichTextChange<PS, SEG, S>>> richTextUndoManager(
            GenericStyledArea<PS, SEG, S> area) {
        return richTextUndoManager(area, UndoManagerFactory.unlimitedHistoryFactory());
    }
public static < PS , SEG , S > UndoManager < List < RichTextChange < PS , SEG , S > > > richTextUndoManager ( GenericStyledArea < PS , SEG , S > area ) { return richTextUndoManager ( area , UndoManagerFactory . unlimitedHistoryFactory ( ) ) ; }
Returns an UndoManager with an unlimited history that can undo/redo {@link RichTextChange}s. New changes
emitted from the stream will not be merged with the previous change
after {@link #DEFAULT_PREVENT_MERGE_DELAY}