@main[]

$h[ $.key[value] ]
^h.foreach[k;v]{ ^test[$h] }

@test[h]
non-blocking hash operations:

^h._count[]
$k[^h._keys[]]
$h2[^hash::create[$h]]
$b[^h.contains[key]]
^h.foreach[k;v]{$k=>$v}
^h._at(0)

hash no longer hash blocking operations:

$h.k[v]
$h.k2[v2]
^json:string[$h]

$h2[ $.k[v] ]
^h.sub[$h2]
^json:string[$h]

^h.delete[k2]
^json:string[$h]