{
  "id": 370663,
  "migration_type": "common_cartridge_importer",
  "migration_type_title": "Canvas Cartridge Importer",
  "migration_issues_url": "https://example.com/api/v1/courses/1/content_migrations/1/migration_issues",
  "attachment": {"url": "https://example.com/api/v1/courses/1/content_migrations/1/download_archive"},
  "progress_url": "https://example.com/api/v1/progress/4",
  "user_id": 4,
  "workflow_state": "running",
  "started_at": "2012-06-01T00:00:00-06:00",
  "finished_at": "2012-06-01T00:00:00-06:00",
  "pre_attachment": {"upload_url": "",  "message": "file exceeded quota", "upload_params": {}}
}