New in version 2.0.
Get first container element starting strictly before prolated_offset:
abjad> staff = Staff("c'8 d'8 e'8 f'8")
abjad> containertools.get_first_element_starting_strictly_before_prolated_offset(staff, Duration(1, 8))
Note("c'8")
Return component.
Return none when container element starts stirctly before prolated_offset.
Changed in version 2.0: renamed containertools.get_rightmost_element_starting_before_prolated_offset() to containertools.get_first_element_starting_strictly_before_prolated_offset().