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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _set_class_path(cls, module_dict=sys.modules):
 """Sets the absolute path to this class as a string. Used by the Pipeline API to reconstruct the Pipeline sub-class object at execution time instead of passing around a serialized function. Args: module_dict: Used for testing. """

    # Do not traverse the class hierarchy fetching the class path attribute.
    found = cls.__dict__.get('_class_path')
    if found is not None:
      return

    # Do not set the _class_path for the base-class, otherwise all children's
    # lookups for _class_path will fall through and return 'Pipeline' above.
    # This situation can happen if users call the generic Pipeline.from_id
    # to get the result of a Pipeline without knowing its specific class.
    if cls is Pipeline:
      return

    class_path = '%s.%s' % (cls.__module__, cls.__name__)
    # When a WSGI handler is invoked as an entry point, any Pipeline class
    # defined in the same file as the handler will get __module__ set to
    # __main__. Thus we need to find out its real fully qualified path.
    if cls.__module__ == '__main__':
      for name, module in module_dict.items():
        if name == '__main__':
          continue
        found = getattr(module, cls.__name__, None)
        if found is cls:
          class_path = '%s.%s' % (name, cls.__name__)
          break
    cls._class_path = class_path