json = pyimport "json"

arr = ["a"]
assert arr in Array(Str)
assert arr in Array(Str, 1)
assert arr notin Array(Int)
assert arr notin Array(Str, 2)

j = json.loads "{ \"a\": [1] }"
assert j in {Str: Obj}
assert j["a"] in Array(Int)
assert j["a"] notin Array(Str)