old_contents: from basecommand import Command
  from listcommand import ListCommand
  from project import ProjectCommand
  
  Command.register()
  Command.register(ProjectCommand)
  Command.register(ListCommand)
  
new_contents: from basecommand import Command
  from listcommand import ListCommand
  from project import ProjectCommand
  from version import VersionCommand
  
  Command.register()
  Command.register(ProjectCommand)
  Command.register(ListCommand)
  Command.register(VersionCommand)
  
subject: add version code