<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def _sync_tasks(self, tasks_json):
 """"Populate the user's tasks from a JSON encoded list."""

        for task_json in tasks_json:
            task_id = task_json['id']
            project_id = task_json['project_id']
            if project_id not in self.projects:
                # ignore orphan tasks
                continue
            project = self.projects[project_id]
            self.tasks[task_id] = Task(task_json, project)