Garden\Schema::filterData PHP Method

    protected function filterData(array &$data, array $schema, Validation &$validation, $path = '')
    {
        foreach ($data as $key => $val) {
            if (array_key_exists($key, $schema)) {
                continue;
            }
            $errorMessage = sprintft('Unexpected parameter: %1$s.', $path . $key);
            switch ($this->validationBehavior) {
                case self::VALIDATE_EXCEPTION:
                    $validation->addError('unexpected_parameter', $key, ['parameter' => $key, 'message' => $errorMessage, 'status' => 500]);
                    continue;
                case self::VALIDATE_NOTICE:
                    trigger_error($errorMessage, E_USER_NOTICE);
                case self::VALIDATE_REMOVE:
                default:
                    unset($data[$key]);
            }
        }
        return $this;
    }