docs: def merge_entries(self, source_entry):
          '''Merge two entries.
  
          Allow the merging of two MFTEntries copying the attributes to the correct
          place and the datastreams.
  
          Args:
              source_entry (:obj:`MFTEntry`) - Source entry where the data will be
                  copied from
          '''
          #TODO should we change this to an overloaded iadd?
          #TODO I really don't like this. We are spending cycles to load things that are going to be discarted. Check another way.
          #copy the attributes
          for list_attr in source_entry.attrs.values():
              for attr in list_attr:
                  self.attrs[attr.header.attr_type_id].append(attr) #add an attribute
          #copy data_streams
          for stream in source_entry.data_streams:
              dest_stream = self._find_datastream(stream.name)
              if dest_stream is not None:
                  dest_stream.add_from_datastream(stream)
              else:
                  self.data_streams.append(stream)