def add_spanning_tree(self, st):
        self.add_nodes(list(st.keys()))
        for each in st:
            if (st[each] is not None):
                self.add_edge((st[each], each))
Return the scope to be used to evaluate ExprEvaluators.
dataset/ETHPy150Open nerdvegas/rez/src/rez/vendor/pygraph/mixins/common.py/common.add_spanning_tree--crossover with--dataset/ETHPy150Open OpenMDAO/OpenMDAO-Framework/openmdao.main/src/openmdao/main/driver.py/Driver.get_expr_scope