== foo ==
fun foo(f: () -> Unit) {
    f()
}
---------------------
L0:
    <START>
    v(f: () -> Unit)
    w(f)
    mark({ f() })
    mark(f())
    r(f)
    call(f, invoke)
L1:
    <END>               NEXT:[<SINK>]
error:
    <ERROR>             PREV:[]
sink:
    <SINK>              PREV:[<ERROR>, <END>]
=====================