def find_by_name(self,name):
        node = self.tab[name]
        if not node:
            node.append(Constant(name))
            node.append(None)
        return self.get_rep_rec(node)[0]
Same as find, but looks up a constant by name, creating a
dataset/ETHPy150Open Microsoft/ivy/src/ivy/ivy_congclos.py/CongClos.find_by_name