fails:String#rstrip when given character selectors arguments removes trailing characters in the intersection of sets removed
fails:String#rstrip when given character selectors arguments negates sets starting with ^
fails:String#rstrip when given character selectors arguments removes trailing characters in a sequence
fails:String#rstrip when given character selectors arguments removes trailing multibyte characters
fails:String#rstrip when given character selectors arguments respects backslash for escaping
fails:String#rstrip when given character selectors arguments tries to convert each argument to a string using to_str
fails:String#rstrip when given character selectors arguments raises a TypeError when an argument can't be converted to a string
fails:String#rstrip when given character selectors arguments returns String instances when called on a subclass
fails:String#rstrip when given character selectors arguments returns a String in the same encoding as self
fails:String#rstrip when given character selectors arguments raises an Encoding::CompatibilityError when the encodings are incompatible
