[Checkins] [zopefoundation/Zope] 428c76: add `__iter__` to `_C2ZContextWrapper`

[Dieter Maurer]

  Branch: refs/heads/fixes4plone+archetypes-4.x
  Home:   https://github.com/zopefoundation/Zope
  Commit: 428c7699f862b142ba39ff97915d2d0801bb049b
      https://github.com/zopefoundation/Zope/commit/428c7699f862b142ba39ff97915d2d0801bb049b
  Author: dieter <dieter at handshake.de>
  Date:   2020-03-29 (Sun, 29 Mar 2020)

  Changed paths:
    M src/Products/PageTemplates/engine.py
    M src/Products/PageTemplates/tests/testC2ZContext.py

  Log Message:
  -----------
  add `__iter__` to `_C2ZContextWrapper`