Help for 'export_vdf milvus':
usage: export_vdf milvus [-h] [-u URI] [-t TOKEN] [-c COLLECTIONS]

options:
  -h, --help            show this help message and exit
  -u URI, --uri URI     Milvus connection URI
  -t TOKEN, --token TOKEN
                        Milvus connection token
  -c COLLECTIONS, --collections COLLECTIONS
                        Names of collections to export

