code: private int appendNextCharacterAndAdvanceLoop(String line, StringBuilder sb, int i) {
          sb.append(line.charAt(i + 1));
          i++;
          return i;
      }
docs: Appends the next character in the line to the stringbuffer.
  
  @param line - line to process
  @param sb   - contains the processed character
  @param i    - current position in the line.
  @return new position in the line.