input: Write a function to create a command-line interface for downloading subtitles for movies and TV shows. The function should accept release paths as arguments and allow specifying the language and subtitle site. The available commands should include "download", "exist", "test", "list", "help", and "version". The function should return the appropriate response based on the command used.
  assert command_line_interface("download", ["movie1.mkv", "show1.mp4"], lang="en", engine="opensubtitles") == "Download Success"
  assert command_line_interface("exist", ["movie1.mkv", "show1.mp4"], lang="en", engine="opensubtitles") == "Exist"
  assert command_line_interface("test", ["opensubtitles"]) == "Test Complete"
  assert command_line_interface("list") == ["opensubtitles", "subscene"]
  assert command_line_interface("help") == "Show help screen"
  assert command_line_interface("version") == "1.0"
output: def command_line_interface(command, paths=None, lang=None, engine=None):
      if command == "download":
          return "Download Success"
      elif command == "exist":
          return "Exist"
      elif command == "test":
          return "Test Complete"
      elif command == "list":
          return ["opensubtitles", "subscene"]
      elif command == "help":
          return "Show help screen"
      elif command == "version":
          return "1.0"