private SPPFNode getExpectedSPPF() {
   NonterminalSymbolNode node1 =
       new NonterminalSymbolNode(grammar.getNonterminalByName("S"), 0, 6);
   NonterminalSymbolNode node2 =
       new NonterminalSymbolNode(grammar.getNonterminalByName("forall"), 0, 6);
   node1.addChild(node2);
   return node1;
 }