code: private static String concatenateStrings(String... stringsToConcatenate) {
          StringBuilder builder = new StringBuilder();
          final int stringsLength = stringsToConcatenate.length;
          for (int i = 0; i < stringsLength; i++) {
              if (i == stringsLength - 1 && stringsLength != 1) {
                  builder.append(" or ");
              } else if (i != 0) {
                  builder.append(", ");
              }
              builder.append(stringsToConcatenate[i]);
          }
          return builder.toString();
      }
docs: Concatenate strings.
  
  @param stringsToConcatenate the strings to concatenate
  @return the string