code: def merge_tops(self, tops):
          '''
          Cleanly merge the top files
          '''
          merging_strategy = self.opts['top_file_merging_strategy']
          try:
              merge_attr = '_merge_tops_{0}'.format(merging_strategy)
              merge_func = getattr(self, merge_attr)
              if not hasattr(merge_func, '__call__'):
                  msg = '\'{0}\' is not callable'.format(merge_attr)
                  log.error(msg)
                  raise TypeError(msg)
          except (AttributeError, TypeError):
              log.warning(
                  'Invalid top_file_merging_strategy \'%s\', falling back to '
                  '\'merge\'', merging_strategy
              )
              merge_func = self._merge_tops_merge
          return merge_func(topsf merge_tops(self, tops):
          '''
          Cleanly merge the top files
          '''
          merging_strategy = self.opts['top_file_merging_strategy']
          try:
              merge_attr = '_merge_tops_{0}'.format(merging_strategy)
              merge_func = getattr(self, merge_attr)
              if not hasattr(merge_func, '__call__'):
                  msg = '\'{0}\' is not callable'.format(merge_attr)
                  log.error(msg)
                  raise TypeError(msg)
          except (AttributeError, TypeError):
              log.warning(
                  'Invalid top_file_merging_strategy \'%s\', falling back to '
                  '\'merge\'', merging_strategy
              )
              merge_func = self._merge_tops_merge
          return merge_func(tops)
docs: Cleanly merge the top files