New in version 2.0.
List prolated durations of leaves in expr:
abjad> staff = Staff(tuplettools.FixedDurationTuplet(Duration(2, 8), "c'8 d'8 e'8") * 2)
abjad> leaftools.list_prolated_durations_of_leaves_in_expr(staff)
[Duration(1, 12), Duration(1, 12), Duration(1, 12), Duration(1, 12), Duration(1, 12), Duration(1, 12)]
Return list of fractions.