An options object must be a plain object (or undefined, for "none") whose own keys
are all in known. A misspelled or unknown key (State, timeout), or a
__proto__ key from JSON.parse, used to be ignored without a word, so
members({ State: "Bayern" }) returned all 193 members. Returns a Problem naming
the first unknown key (cut, JSON-quoted) and the known ones.
An options object must be a plain object (or
undefined, for "none") whose own keys are all inknown. A misspelled or unknown key (State,timeout), or a__proto__key fromJSON.parse, used to be ignored without a word, somembers({ State: "Bayern" })returned all 193 members. Returns aProblemnaming the first unknown key (cut, JSON-quoted) and the known ones.