docs: def _get_best_merge(routing_table, aliases):
      """Inspect all possible merges for the routing table and return the merge
      which would combine the greatest number of entries.
  
      Returns
      -------
      :py:class:`~.Merge`
      """
      # Create an empty merge to start with
      best_merge = _Merge(routing_table)
      best_goodness = 0
  
      # Look through every merge, discarding those that are no better than the
      # best we currently know about.
      for merge in _get_all_merges(routing_table):
          # If the merge isn't sufficiently good ignore it and move on
          if merge.goodness <= best_goodness:
              continue
  
          # After the merge refines itself to remove entries which would either
          # be aliased under other entries or entries which would cause the
          # aliasing of other entries we check if it is better than the current
          # best merge and reject it if it isn't.
          merge = _refine_merge(merge, aliases, min_goodness=best_goodness)
          if merge.goodness > best_goodness:
              # The merge we now have a reference to is better than the best
              # merge that we've previously encountered.
              best_merge = merge
              best_goodness = merge.goodness
  
      # Return the best merge and the best goodness for the calling method
      return best_merge