/**
* UserEntity is the 'Owning side'
* @see http://docs.doctrine-project.org/projects/doctrine-orm/en/latest/reference/association-mapping.html#owning-and-inverse-side-on-a-manytomany-association
* @param GroupEntity $group
*/
public function addGroup(GroupEntity $group)
{
$group->addUser($this);
$this->groups[] = $group;
}
