Insert component into container at index i. Fracture spanners to the left of index i. Fracture spanners to the right of index i. Return Python list of fractured spanners.
For nonfracturing insert, use Container.__setitem__.
Example:
abjad> t = Voice(construct.scale(4))
abjad> Beam(t[:])
abjad> containertools.insert_and_fracture(t, 1, Rest((1, 4)))
abjad> print t.format
\new Voice {
c'8 [ ]
r4
d'8 [
e'8
f'8 ]
}