public function getRelations()
    {
        if (empty($this->_relations)) {
            $properties = $this->getInspector()->getClassProperties();
            foreach ($properties as $property) {
                $annotations = $this->getInspector()
                    ->getPropertyAnnotations($property);
                foreach (static::$_annotations as $name => $class) {
                    if ($annotations->hasAnnotation($name)) {
                        $this->_relations[$property] = call_user_func_array(
                            [$class, 'create'],
                            [
                                $annotations->getAnnotation($name),
                                $this->getEntity(),
                                trim($property, '_')
                            ]
                        );
                        break;
                    }
                }
            }
        }
        return $this->_relations;
    }