public static Config.Parser <From, B> map <From, A, B>( this Config.Parser <From, A> aParser, Func <A, B> f ) => aParser.map((path, a) => f(a));
public static Config.Parser <B> map <A, B>(this Config.Parser <A> aParser, Fn <A, B> f) => aParser.map((path, a) => f(a));