protected void serialize ( DataTree dt , Map < Long , Long > sessions , OutputArchive oa , FileHeader header ) throws IOException { // this is really a programmatic error and not something that can // happen at runtime if ( header == null ) throw new IllegalStateException ( "Snapshot's not open for writing: uninitialized header" ) ; header . serialize ( oa , "fileheader" ) ; SerializeUtils . serializeSnapshot ( dt , oa , sessions ) ; }
serialize the datatree and sessions