stderr:
<REPL Input>:1:1: error: value of type 'String' has no member 'character' "test".character(at: 0) ^~~~~~ ~~~~~~~~~ Swift.String:10:16: note: did you mean 'characters'? public var characters: String.CharacterView { get set } ^ Swift.String:8:16: note: did you mean '_characters'? public var _characters: String._CharacterView { get set } ^
(edited)