protected function setValidationVariables(array $data, $nestedKey = null)
    {
        foreach ($data as $key => $value) {
            // Add support for nested arrays
            $key = ! empty($nestedKey) ? $nestedKey.'.'.$key : $key;

            // If value is an array, we need to created a nested key
            // until we reach the final value.
            if (is_array($value)) {
                $this->setValidationVariables($value, $key);
            } else {
                $this->variables['{:'.$key.'}'] = $value;
            }
        }

        return $this;
    }