'Run various validation checks on the message.  Some validations
are only performed if the catalog is provided.  This method returns
a sequence of `TranslationError` objects.
:rtype: ``iterator``
:param catalog: A catalog instance that is passed to the checkers
:see: `Catalog.check` for a way to perform checks for all messages
in a catalog.'

def check(self, catalog=None):

    from babel.messages.checkers import checkers
    errors = []
    for checker in checkers:
        try:
            checker(catalog, self)
        except TranslationError as e:
            errors.append(e)
    return errors
