New in version 2.0.
Yield components grouped by preprolated duration:
abjad> notes = notetools.make_notes([0], [(1, 4), (1, 4), (1, 8), (1, 16), (1, 16), (1, 16)])
abjad> for x in componenttools.yield_components_grouped_by_preprolated_duration(notes):
... x
...
(Note("c'4"), Note("c'4"))
(Note("c'8"),)
(Note("c'16"), Note("c'16"), Note("c'16"))
Return generator.