old_contents: 
  
  class Transport(object):
      """
      This class recieves the ``sys.argv`` list and will call the dictionary 
      mappings when they match the subcommands.
  
      :param arguments: Should be the *exact* list of arguments coming from ``sys.argv``
      :keyword mapper: A dictionary of mapped subcommands to classes
      """
  
  
      def __init__(self, arguments, mapper=None):
          self.arguments = arguments
          self.mapper = mapper
  
  
      def dispatch(self):
          pass
  
new_contents: 
  
  class Transport(object):
      """
      This class recieves the ``sys.argv`` list and will call the dictionary
      mappings when they match the subcommands.
  
      :param arguments: Should be the *exact* list of arguments coming from ``sys.argv``
      :keyword mapper: A dictionary of mapped subcommands to classes
      """
  
  
      def __init__(self, arguments, mapper=None):
          self.arguments = arguments
          self.mapper = mapper or {}
  
  
      def dispatch(self):
          mapper_keys = self.mapper.keys()
          for arg in self.arguments:
              if arg in mapper_keys:
                  instance = self.mapper.get(arg)(self.arguments)
                  return instance.parse_args()
  
subject: make the dispatcher do some work