rent.Key</a> may not change. 
            If either the key or the data is partial <a href="T_BerkeleyDB_DatabaseEntry.htm">DatabaseEntry</a>,
            its <a href="P_BerkeleyDB_DatabaseEntry_PartialLen.htm">PartialLen</a> bytes starting
            <a href="P_BerkeleyDB_DatabaseEntry_PartialOffset.htm">PartialOffset</a> bytes from the beginning
            of the retrieved data record are returned as if they comprised the
            entire record. If any or all of the specified bytes do not exist
     