New in version 2.0.
Get first container element starting at or after prolated_offset:
abjad> staff = Staff("c'8 d'8 e'8 f'8")
abjad> containertools.get_first_element_starting_at_or_after_prolated_offset(staff, Duration(1, 8))
Note("d'8")
Return component.
Return none when no container element starts at or after prolated_offset.
Changed in version 2.0: renamed containertools.get_leftmost_element_starting_not_before_prolated_offset() to containertools.get_first_element_starting_at_or_after_prolated_offset().