Returns the boundary following the current boundary. If the current boundary
is the last text boundary, it returns BreakIterator.DONE and
the iterator's current position is unchanged. Otherwise, the iterator's
current position is set to the boundary following the current boundary.
BreakIterator.DONE if the current boundary is the last text
boundary.
Equivalent to next(1).
next(int)
Diagram: BreakIterator