fails:String#each_line splits using default newline separator when none is specified
fails:String#each_line splits self using the supplied record separator and passes each substring to the block
fails:String#each_line taints substrings that are passed to the block if self is tainted
fails:String#each_line passes self as a whole to the block if the separator is nil
fails:String#each_line yields paragraphs (broken by 2 or more successive newlines) when passed ''
fails:String#each_line uses $/ as the separator when none is given
fails:String#each_line yields subclass instances for subclasses
fails:String#each_line returns self
fails:String#each_line tries to convert the separator to a string using to_str
fails:String#each_line does not care if the string is modified while substituting
fails:String#each_line raises a TypeError when the separator can't be converted to a string
fails:String#each_line accepts a string separator
fails:String#each_line raises a TypeError when the separator is a symbol
fails:String#each_line returns an enumerator when no block given
