static File createSegmentFile(String name,File directory,long id,long version){
  return new File(directory,String.format("%s-%d-%d.log",Assert.notNull(name,"name"),id,version));
}

static File createSegmentFile ( String name , File directory , long id , long version ) { return new File ( directory , String . format ( "%s-%d-%d.log" , Assert . notNull ( name , "name" ) , id , version ) ) ; }
creates a segment file for the given directory , log name , segment id , and segment version .
