public function hasInstance($id): bool
    {
        $id = $this->dereference($id);

        return isset($this->instances[$id]);
    }
public function hasInstance($id): bool
    {
        $id = $this->dereference($id);

        return isset($this->instances[$id]);
    }
public function hasInstance ( $ id ) : bool { $ id = $ this -> dereference ( $ id ) ; return isset ( $ this -> instances [ $ id ] ) ; }
Returns a value indicating whether the container has already instantiated
instance of the specified name.
@param string $id class name, interface name or alias name
@return bool whether the container has instance of id specified.
@throws CircularReferenceException
Returns a value indicating whether the container has already instantiated instance of the specified name .