protected function load()
	{
		$this->assignments = [];
		$assignments = DiscHelper::loadFromFile($this->assignmentFile);
		$assignmentsMtime = @filemtime($this->assignmentFile);
		
		foreach ($assignments as $userId => $roles) {
			foreach ($roles as $role) {
				$this->assignments[$userId][$role] = new Assignment([
					'userId' => $userId,
					'roleName' => $role,
					'createdAt' => $assignmentsMtime,
				]);
			}
		}
	}