def METHOD_NAME():
  print 'Usage: ', prog_name, ' [options]'
  print 'Options:'
  print '   -h | --help             : Print usage and exit'
  print '   --output_dir <dir>      : data directory for output'
  print '                             (default = ', opt_output_dir, ')'
  print '   --input_dir <dir>      : data directory for output'
  print '                             (default = ', opt_input_dir, ')'