src/Container/src/AbstractContainer.php
protected function isResolvableService(string $id): bool
    {
        return isset($this->keys[$id]) || class_exists($id);
    }
protected function isResolvableService(string $id): bool
    {
        return isset($this->keys[$id]) || class_exists($id);
    }
protected function isResolvableService ( string $ id ) : bool { return isset ( $ this -> keys [ $ id ] ) || class_exists ( $ id ) ; }
Check if container can resolve the service with subject identifier.

@param string $id
@return bool
Check if container can resolve the service with subject identifier .