== foo ==
fun foo(a: Array<Int>) {
    a[1] = 2
}
---------------------
L0:
    <START>
    v(a: Array<Int>)
    w(a)
    mark({ a[1] = 2 })
    mark(a[1])
    r(a)
    r(1)
    r(2)
    call(a[1], set)
L1:
    <END>                 NEXT:[<SINK>]
error:
    <ERROR>               PREV:[]
sink:
    <SINK>                PREV:[<ERROR>, <END>]
=====================