hostgroupMembershipResolver === null) { $this->hostgroupMembershipResolver = new HostGroupMembershipResolver( $this->getConnection() ); } return $this->hostgroupMembershipResolver; } public function setHostGroupMembershipResolver(HostGroupMembershipResolver $resolver) { $this->hostgroupMembershipResolver = $resolver; return $this; } protected function notifyResolvers() { $resolver = $this->getHostGroupMembershipResolver(); $resolver->addGroup($this); $resolver->refreshDb(); return $this; } }