code: def guess_backend(identifier):
      
      if identifier.startswith('usb://') or identifier.startswith('0x'):
          return 'pyusb'
      elif identifier.startswith('file://') or identifier.startswith('/dev/usb/') or identifier.startswith('lp'):
          return 'linux_kernel'
      elif identifier.startswith('tcp://'):
          return 'network'
      else:
          raise ValueError('Cannot guess backend for given identifier: %s' % identifier)
docs: guess the backend from a given identifier string for the device