code: func (db *DB) CheckSchemaVersion() error {
  	schemaVersion, err := db.SchemaVersion()
  	if err != nil {
  		return fmt.Errorf("error fetching schema version: %v", err)
  	}
  
  	expectedSchemaVersion := db.schema().latestSchema()
  	if schemaVersion != expectedSchemaVersion {
  		return &IncompatibleSchemaError{
  			SchemaVersion:         schemaVersion,
  			ExpectedSchemaVersion: expectedSchemaVersion,
  		}
  	}
  
  	return nil
  }
docs: // CheckSchemaVersion verifies that the actual database schema matches the
  // version that this version of Empire expects.