def depth_first_order(self):
        if hasattr(self, '_children'):
            ret = [self]
            for child in self.get_children():
                ret.extend(child.depth_first_order())
            return ret
        else:
            return [self] + list(self.get_descendants().order_by('path'))
Return true if the meta data with the given classification appears
dataset/ETHPy150Open fusionbox/django-widgy/widgy/models/base.py/Node.depth_first_order--crossover with--dataset/ETHPy150Open moloney/dcmstack/src/dcmstack/dcmmeta.py/NiftiWrapper.meta_valid