/**
  * Implements corresponding isValidXX logic.
  *
  * @param string $context   Please see corresponding isValidXX description.
  * @param string $input     Please see corresponding isValidXX description.
  * @param int    $minValue  Please see corresponding isValidXX description.
  * @param int    $maxValue  Please see corresponding isValidXX description.
  * @param bool   $allowNull Please see corresponding isValidXX description.
  *
  * @return does not return a value.
  * @throws ValidationException thrown if input is invalid.
  * @throws IntrusionException thrown if intrusion is detected.
  */
 private function _assertValidInteger($context, $input, $minValue, $maxValue, $allowNull)
 {
     $nvr = new IntegerValidationRule('IntegerValidator', $this->_encoder, $minValue, $maxValue);
     $nvr->setAllowNull($allowNull);
     $nvr->assertValid($context, $input);
     return null;
 }