Package of classes used instantiating objects written with pre-version 5 versions of HBase. Under the hbase.rootdir, a file named hbase.version holds the version number for the data persisted by HBase. The version number is upped every time a change is made in HBase on-filesystem formats. Version 0.2.0 of HBase shipped with an on-filesystem version of 5. This package holds classes from previous to version 5 used during the migration of an HBase instance up to version 5. See How To Migrate for more on the migration of HBase across versions and for notes on design of the HBase migration system.