Delete contents of container:
abjad> staff = Staff("c'8 d'8 e'8 f'8")
abjad> spannertools.BeamSpanner(staff.leaves)
BeamSpanner(c'8, d'8, e'8, f'8)
abjad> f(staff)
\new Staff {
c'8 [
d'8
e'8
f'8 ]
}
abjad> containertools.delete_contents_of_container(staff)
[Note("c'8"), Note("d'8"), Note("e'8"), Note("f'8")]
abjad> f(staff)
\new Staff {
}
Return container contents.
Changed in version 2.0: renamed containertools.contents_delete() to containertools.delete_contents_of_container().