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**CHANGES**
- Rename the product name "Sorna" to "Backend.AI".
- Package import path: "sorna" → "ai.backend.client"
- Class names: "SornaError" / "SornaAPIError" → "BackendError" / "BackendAPIError"
- Any mention of "Sorna" in the API headers → "BackendAI".
e.g., "X-Sorna-Version" API request header → "X-BackendAI-Version"
- Refactor the internal structure for sync/async API functions.
- Add support for the Admin API based on GraphQL both in the CLI and the functions.
Now you can list up details of your compute sessions with ease.