VersionCmp compares versions a and b and returns -1 if a < b, +1 if a > b and 0 if they are equal.

ErrUnsupportedSchemaVersion is returned when a Persistable model cannot be persisted in a particular schema version.

NoData is a model with no data to persist.

OldestSupportedSchemaVersion is the oldest version of the schema that lily can convert its models to Models can be persisted using any version between this and the latest version.

A Version represents a version of a model schema.

A Persistable can persist a full copy of itself or its components as part of a storage batch using a specific version of a schema.

A Storage can marshal models into a serializable format and persist them.

A StorageBatch persists a model to storage as part of a batch such as a transaction.

A PersistableList is a list of Persistables that should be persisted together.