code: func NewLineDelimiter(output io.Writer, delimiter string) *LineDelimiter {
  	return &LineDelimiter{output: output, delimiter: []byte(delimiter)}
  }
docs: // NewLineDelimiter allocates a new io.Writer that will split input on lines
  // and bracket each line with the delimiter string.  This can be useful in
  // output tests where it is difficult to see and test trailing whitespace.