something like ``` import lib.Decoder as D val d...

# random

[danneu]

something like

import lib.Decoder as D

val decoder: Decoder<Pair<Username, Password?>> = D.tuple(D.string, D.nullable(D.string))

decoder.decode("""["user1", "secret"]""") == "user1" to "secret"
decoder.decode("""["user2", null]""")  == "user2" to null