public static Option <R> Map <T, R>(this Option.None _, Func <T, R> func) => None;
public bool Equals(Option.None _) => isNone;
public bool Equals(Option.None _) => !_isSome;
public static Option <R> Map <T, R>(this Option.None _, Func <T, R> func) => None;
public bool Equals(Option.None _) => isNone;
public bool Equals(Option.None _) => !_isSome;