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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def ancestors(self, recurs=True, context=None):
 """Iterate over the base classes in prefixed depth first order. :param recurs: Whether to recurse or return direct ancestors only. :type recurs: bool :returns: The base classes :rtype: iterable(NodeNG) """

        # FIXME: should be possible to choose the resolution order
        # FIXME: inference make infinite loops possible here
        yielded = {self}
        if context is None:
            context = contextmod.InferenceContext()
        if not self.bases and self.qname() != "builtins.object":
            yield builtin_lookup("object")[1][0]
            return

        for stmt in self.bases:
            with context.restore_path():
                try:
                    for baseobj in stmt.infer(context):
                        if not isinstance(baseobj, ClassDef):
                            if isinstance(baseobj, bases.Instance):
                                baseobj = baseobj._proxied
                            else:
                                continue
                        if not baseobj.hide:
                            if baseobj in yielded:
                                continue
                            yielded.add(baseobj)
                            yield baseobj
                        if not recurs:
                            continue
                        for grandpa in baseobj.ancestors(recurs=True, context=context):
                            if grandpa is self:
                                # This class is the ancestor of itself.
                                break
                            if grandpa in yielded:
                                continue
                            yielded.add(grandpa)
                            yield grandpa
                except exceptions.InferenceError:
                    continue