src/Resource/AbstractResource.php
private function internalGet(array $array, $key, $exists = false)
    {
        if (isset($array[$key])) {
            return (!$exists) ? $array[$key] : true;
        }

        $parts = explode('.', $key);

        foreach ($parts as $part) {
            if (!is_array($array) || !isset($array[$part])) {
                return (!$exists) ? null : false;
            }

            $array = $array[$part];
        }

        return (!$exists) ? $array : true;
    }
private function internalGet(array $array, $key, $exists = false)
    {
        if (isset($array[$key])) {
            return (!$exists) ? $array[$key] : true;
        }

        $parts = explode('.', $key);

        foreach ($parts as $part) {
            if (!is_array($array) || !isset($array[$part])) {
                return (!$exists) ? null : false;
            }

            $array = $array[$part];
        }

        return (!$exists) ? $array : true;
    }
The internal get function for getting values by their key

@param array $array  The array to use -- will always be $this->content
@param mixed $key    The key to find the value for
@param bool  $exists Whether to return null or false dependant on the calling function

@return array|bool|null The resource key value