code: public static String fill(
              final String prefix,
              final String charSequence,
              final int times) {
          if (times < 1) {
              return "";
          }
          StringBuilder sb = new StringBuilder();
          if (prefix != null) {
              sb.append(prefix);
          }
          for (int i = 0; i < times; i++) {
              sb.append(charSequence);
          }
          return sb.toString();
      }
docs: Create a string representation repeating a character
  sequence the requested number of times.
  @param prefix an optional prefix to prepend
  @param charSequence the character sequence to repeat
  @param times how many times the character sequence should be repeated
  @return a string filled with character sequence or empty string