code: def register_callback_duplicate(self, func, serialised=True):
          
          self.__client.register_callback_duplicate(partial(self.__callback_payload_only, func), serialised=serialised)
docs: Register a callback for resource creation but where the resource already exists in Iotic Space.
          In this case the existing reference is passed to you.
          If `serialised` is not set, the callbacks might arrive in a different order to they were requested.
  
          The payload passed to your callback is an OrderedDict with the following keys
  
              #!python
              r         : R_ENTITY, R_FEED, etc # the type of existing resource
              lid       : <name>                # the local name of the
                                                # existing resource
              id        : <GUID>                # the global Id of the
                                                # existing resource
              epId      : <GUID>                # the global Id of your agent
  
          `Note` resource types are defined [here](../Core/Const.m.html)
  
          `Example`
  
              #!python
              def duplicated_callback(args):
                  print(args)
              ...
              client.register_callback_created(duplicated_callback)
  
          This would print out something like the following on re-creation of an R_ENTITY
  
              #!python
              OrderedDict([(u'lid', u'new_thing1'), (u'r', 1),
                           (u'epId', u'ffd47b75ea786f55c76e337cdc47665a'),
                           (u'id', u'3f11df0a09588a6a1a9732e3837765f8')]))