question: public static void syncModificationTimes ( Configuration conf , Path src , Path dest , Optional < PathFilter > filter ) throws IOException { Set < FileStatus > srcFileStatuses = getFileStatusesRecursive ( conf , src , filter ) ; Map < String , Long > srcFileModificationTimes = null ; try { srcFileModificationTimes = getRelativePathToModificationTime ( src , srcFileStatuses ) ; } catch ( ArgumentException e ) { throw new IOException ( "Invalid file statuses!" , e ) ; } FileSystem destFs = dest . getFileSystem ( conf ) ; for ( String file : srcFileModificationTimes . keySet ( ) ) { destFs . setTimes ( new Path ( dest , file ) , srcFileModificationTimes . get ( file ) , - 1 ) ; } }
target:  Set the file modification times for the files on the destination to be the same as the modification times for the file on the source.