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

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

        return isset($this->definitions[$id]);
    }
public function has ( $ id ) : bool { $ id = $ this -> dereference ( $ id ) ; return isset ( $ this -> definitions [ $ id ] ) ; }
Returns a value indicating whether the container has the definition of the specified name.
@param string $id class name, interface name or alias name
@return bool whether the container is able to provide instance of id specified.
@throws CircularReferenceException
@see set()
Returns a value indicating whether the container has the definition of the specified name .