code: protected final List<ValidationException> contOnValidationError(final ValidationTask... validationTasks) {
          final List<ValidationException> errors = new ArrayList<>();
          for (final ValidationTask validationTask:  validationTasks) {
              if (!validationTask.isRequired() && validationTask.getInput() == null) {
                  continue;
              }
              if (!validationTask.getPattern().matcher(validationTask.getInput()).matches()) {
                  errors.add(new ValidationException(validationTask.getInput(), validationTask.getErrorMessage()));
              }
          }
          return errors;
      }
docs: Given one or mote ValidationTasks, this method will return a List of
  ValidationErrors. If the size of the List is 0, no errors were encountered
  during validation.
  
  Usage:
  <pre>
  List&lt;ValidationException&gt; errors = contOnValidationError(
  new ValidationTask(pattern, input, errorMessage),
  new ValidationTask(pattern, input, errorMessage)
  );
  // If validation fails, this line will be reached.
  </pre>
  
  @param validationTasks an array of one or more ValidationTasks
  @return a List of zero or more ValidationException
  @since 1.0.0