public function build($class)
    {
        if(!isset($this->_properties))
            throw new Exception("A schema must have properties");

        return new Schema($class, array(
            'properties' => $this->_properties,
            'relationships' => $this->_relationships,
            'getters' => $this->_getters,
            'setters' => $this->_setters,
            'events' => $this->_events
        ));
    }