code: public void append(String str, String indentation) {
  		if (indentation.isEmpty()) {
  			append(str);
  		} else if (str != null)
  			append(indentation, str, segments.size());
  	}
docs: Add the given string to this sequence. The given indentation will be prepended to
  each line except the first one if the object has a multi-line string representation.
  
  @param str
  the appended string.
  @param indentation
  the indentation string that should be prepended. May not be <code>null</code>.
  @since 2.11