servicegroupMembershipResolver === null) { $this->servicegroupMembershipResolver = new ServiceGroupMembershipResolver( $this->getConnection() ); } return $this->servicegroupMembershipResolver; } public function setServiceGroupMembershipResolver(ServiceGroupMembershipResolver $resolver) { $this->servicegroupMembershipResolver = $resolver; return $this; } protected function notifyResolvers() { $resolver = $this->getServiceGroupMembershipResolver(); $resolver->addGroup($this); $resolver->refreshDb(); return $this; } }