code: public static List<String> createSubjectList(int number, String stringFormat) {
                  Validate.notNegative(number);
                  Validate.notNull(stringFormat);
                  List<String> result = new ArrayList<>(number);
                  for (int i = 1; i <= number; i++) {
                          result.add(String.format(stringFormat, i));
                  }
                  return result;
          }
docs: Creates a list of subject names in the given format with the given
  size.
  
  @param number Number of subjects to create.
  @param stringFormat The format for subject names.
  @return A list of subject names.
  @throws ParameterException