code: private static String createRowSeperator(List<Integer> maxColumnSizes) {
      StringBuilder rowSeparator = new StringBuilder("+");
      for (int maxColumnSize : maxColumnSizes) {
        rowSeparator.append(Strings.repeat("-", maxColumnSize + 2)).append("+");
      }
      return rowSeparator.append("\n").toString();
    }
docs: Creates the row separator given the maximum size for each column
  
  @param maxColumnSizes the maximum size for each column
  @return the row separator