creator   : ImmutablePoint(x=3.5, y=7.2)
round-trip: {"x":3.5,"y":7.2}
unwrapped : {"street":"123 Main St","city":"Springfield","customerName":"Alice"}
any-setter: {surprise=1, another=[true, false]}
any-getter: {"knownField":"a","surprise":1,"another":[true,false]}
