[Zope3-Users] Where has "validateMapping" gone ?

[Sakesun Roykiattisak]

"zope.schema.validateMapping" was mentioned several times in 
"zope/schema/README.txt"

    $ python
    >>> class Bookmark:
    ...     def __init__(self, url):
    ...         self.url = url
    ...
    >>> from zope.schema import TextLine, validateMapping
    >>> from zope.interface import Interface
    >>> class IBookmark(Interface):
    ...     url = TextLine(title=u'url of the bookmark')
    ...
    ...
    >>> obj = Bookmark(u'zope website', u'http://www.zope.org',
    ...                keywords=('web', 'python'))
    >>> validateMapping(IBookmark, obj.__dict__)



But I cannot find "validateMapping" anywhere besides README.txt. Where 
has it gone ?