New in version 2.0.
Get container element starting at exactly prolated_offset:
abjad> voice = Voice("c'8 d'8 e'8 f'8 g'8 a'8 b'8 c''8")
abjad> containertools.get_element_starting_at_exactly_prolated_offset(voice, Duration(6, 8))
Note("b'8")
Raise missing component error when no container element starts at exactly prolated_offset.
Changed in version 2.0: renamed containertools.get_element_starting_at_prolated_offset() to containertools.get_element_starting_at_exactly_prolated_offset().