text: /*expected
  initial->s1_1->s1_2->s1_3->s1_5->s1_6;
  s1_1->s1_6;
  s1_2->s1_4->s1_5;
  s1_6->final;
  */
  a ??= b ? c : d;
  
  /*DOT
  digraph {
      node[shape=box,style="rounded,filled",fillcolor=white];
      initial[label="",shape=circle,style=filled,fillcolor=black,width=0.25,height=0.25];
      final[label="",shape=doublecircle,style=filled,fillcolor=black,width=0.25,height=0.25];
      s1_1[label="Program:enter\nExpressionStatement:enter\nAssignmentExpression:enter\nIdentifier (a)"];
      s1_2[label="ConditionalExpression:enter\nIdentifier (b)"];
      s1_3[label="Identifier (c)"];
      s1_5[label="ConditionalExpression:exit"];
      s1_6[label="AssignmentExpression:exit\nExpressionStatement:exit\nProgram:exit"];
      s1_4[label="Identifier (d)"];
      initial->s1_1->s1_2->s1_3->s1_5->s1_6;
      s1_1->s1_6;
      s1_2->s1_4->s1_5;
      s1_6->final;
  }
  */
  