question: public void serialize ( DataOutput out ) throws IOException { out . writeUTF ( id ) ; out . writeUTF ( version ) ; out . writeInt ( sourceFiles . size ( ) ) ; for ( Entry < String , List < RevisionFile > > e : sourceFiles . entrySet ( ) ) { out . writeUTF ( e . getKey ( ) ) ; List < RevisionFile > files = e . getValue ( ) ; out . writeInt ( files . size ( ) ) ; for ( RevisionFile file : files ) { out . writeUTF ( file . fileName ) ; out . writeLong ( file . size ) ; } } }
target:  Serialize the token data for communication between server and client. 