message: Fixes nest to use a single chain of elif in map_structure.
diff: @@ -142,7 +142,7 @@ def _sequence_like(instance, args):
  return d
  else:
  return instance_type((key, result[key]) for key in instance)
  - if _is_mapping_view(instance):
  + elif _is_mapping_view(instance):
  # We can't directly construct mapping views, so we create a list instead
  return list(args)
  elif _is_namedtuple(instance) or _is_attrs(instance):
  