code: def merge(self: 'FetchResponse', other: 'FetchResponse') \
              -> 'FetchResponse':
          
          if self.seq != other.seq:
              raise ValueError(other)
          new_data = OrderedDict(self.data)
          new_data.update(other.data)
          return FetchResponse(self.seq, list(new_data.items()))
docs: Merge the other FETCH response, adding any fetch attributes that do
          not already exist in this FETCH response. For example::
  
              * 3 FETCH (UID 119)
              * 3 FETCH (FLAGS (\\Seen))
  
          Would merge into::
  
              * 3 FETCH (UID 119 FLAGS (\\Seen))
  
          Args:
              other: The other response to merge.