public function removeUser(User $user): bool
	{
		if(!$this->isPersisted)
		{
			throw new LogicException('You can only remove a user from a group that exist in the database.');
		}

		if(!$user->isPersisted())
		{
			throw new LogicException('You can only remove a user that exist in the database from a group.');
		}

		return $this->users()->unlink($user);
	}