Multiple argument validation in Extbase

BaseController.php

<?php

class Tx_MyExt_Controller_BaseController extends Tx_Extbase_MVC_Controller_ActionController {

	/**
	 * @see Tx_Extbase_MVC_Controller_ActionController::callActionMethod()
	 */
	protected function callActionMethod() {
		$this->validateAll();
		parent::callActionMethod();
	}

	/**
	 * Implement controller action annotation @validateAll.
	 *
	 * Example: @validateAll $foo $bar Tx_MyExt_Validation_Validator_FooBarValidator
	 *
	 * This will call Tx_MyExt_Validation_Validator_FooBarValidator->isValidAll($foo, $bar)
	 *
	 * @see Tx_Extbase_MVC_Controller_ActionController::callActionMethod()
	 */
	protected function validateAll() {
		$methodTagsValues = $this->reflectionService->getMethodTagsValues(get_class($this), $this->actionMethodName);
		if (isset($methodTagsValues['validateAll'])) {
			foreach ($methodTagsValues['validateAll'] as $validateAll) {
				$split = preg_split('/\s+/', $validateAll);

				$arguments = array();
				foreach ($split as $part) {
					if (substr($part, 0, 1) === '$') {
						$arguments[] = $this->arguments->getArgument(substr($part, 1));
					} else if (substr($part, 0, 3) === 'Tx_') {
						$validatorClass = $part;
					}
				}

				$argumentValues = array();
				foreach ($arguments as $argument) {
					$argumentValues[] = $argument->getValue();
				}

				$validator = $this->objectManager->get($validatorClass);
				call_user_func_array(array($validator, 'isValidAll'), $argumentValues);
				foreach ($validator->getErrors() as $error) {
					$this->argumentsMappingResults->addError($error, $error->getPropertyName());
				}
			}
		}
	}
}

EqualsValidator.php

<?php

class Tx_MyExt_Validation_Validator_EqualsValidator extends Tx_Extbase_MVC_Controller_ArgumentsValidator {
    
    /**
     * Checks if $a equals $b
     * 
     * @param mixed $a
     * @param mixed $b
     */
    public function isValidAll($a, $b) {        
        if ($a !== $b) {
            $error = t3lib_div::makeInstance('Tx_Extbase_MVC_Controller_ArgumentError', 'foo');
            $error->addErrors(array(t3lib_div::makeInstance('Tx_Extbase_Validation_Error', 'A and B are not equal.', 'notEqual')));
            $this->errors[] = $error;
        }
    }
}