'Iterates through all the entries in the catalog, in the order they
were added, yielding a `Message` object for every entry.
:rtype: ``iterator``'

def __iter__(self):

    buf = []
    for (name, value) in self.mime_headers:
        buf.append(('%s:    %s' % (name, value)))
    flags = set()
    if self.fuzzy:
        flags |= set(['fuzzy'])
    (yield Message(u'', '\n'.join(buf), flags=flags))
    for key in self._messages:
        (yield self._messages[key])
