code: def usage():
      print("Usage: $0 [-extension/extensions] <list of names>")
      print("       -extension for one image with full extension")
      print("       -extensions for image list with full extensions")
      sys.exit(1)
  
imports: import sys
  import glob
label_desc: Use image node_id 1 for calling a global function with example usage: usage() without return types