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