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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 _init_c2ps(self, go_sources, traverse_child):
 """Traverse up children."""

        if not traverse_child:
            return {}
        c2ps = defaultdict(set)
        goids_seen = set()
        go2obj = self.go2obj
        for goid_src in go_sources:
            goobj_src = go2obj[goid_src]
            if goid_src not in goids_seen:
                ##F self._traverse_child_objs(c2ps, goobj_src, go2obj, goids_seen)
                self._traverse_child_objs(c2ps, goobj_src, goids_seen)
        return c2ps