IsValidKey checks if the key name is valid.

IsValidStoreName checks if the store name is valid.

NewManager creates a new state manager.

ErrKeyAlreadyExists is returned when a key already exists in a store and cannot be created.

ErrKeyNotFound is returned when a key is not found in a store.

ErrRevisionMismatch is returned when a revision does not match the current revision of a key.

ErrStoreNotFound is returned when a store is not found.