protected function getParentChildKeys($key)
    {
        $parts = explode('.', $key);
        $child = array_pop($parts);
        return [implode('.', $parts), $child];
    }
protected function getParentChildKeys($key)
    {
        $parts = explode('.', $key);
        $child = array_pop($parts);
        return [implode('.', $parts), $child];
    }
protected function getParentChildKeys ( $ key ) { $ parts = explode ( '.' , $ key ) ; $ child = array_pop ( $ parts ) ; return [ implode ( '.' , $ parts ) , $ child ] ; }
Get the parent key, and the child part of the key.

@param string $key The key to get the parent and child part from
@return array The parent and child part
Get the parent key and the child part of the key .