src/Validation/Spec/AbstractValidator.php
protected function dataGet($key, $default = null)
    {
        if (!isset($this->document->data)) {
            return $default;
        }

        return data_get($this->document->data, $key, $default);
    }
protected function dataGet($key, $default = null)
    {
        if (!isset($this->document->data)) {
            return $default;
        }

        return data_get($this->document->data, $key, $default);
    }
Get a value from the document data object use dot notation.

@param string|array $key
@param mixed $default
@return mixed|null