docs: public synchronized TextBox addLine(String line) {
          StringBuilder bob = new StringBuilder();
          for(int i = 0; i < line.length(); i++) {
              char c = line.charAt(i);
              if(c == '\n' && style == Style.MULTI_LINE) {
                  String string = bob.toString();
                  int lineWidth = TerminalTextUtils.getColumnWidth(string);
                  lines.add(string);
                  if(longestRow < lineWidth + 1) {
                      longestRow = lineWidth + 1;
                  }
                  addLine(line.substring(i + 1));
                  return this;
              }
              else if(Character.isISOControl(c)) {
                  continue;
              }
  
              bob.append(c);
          }
          String string = bob.toString();
          if(!validated(string)) {
              throw new IllegalStateException("TextBox validation pattern " + validationPattern + " does not match the supplied text");
          }
          int lineWidth = TerminalTextUtils.getColumnWidth(string);
          lines.add(string);
          if(longestRow < lineWidth + 1) {
              longestRow = lineWidth + 1;
          }
          invalidate();
          return this;
      }