Program (script) @1:1
└─ FunctionDeclaration "fn" @1:1
   └─ body
      └─ FunctionBody @2:5
         └─ ForStatement @2:5
            ├─ init
            │  └─ UsingDeclaration @2:10
            │     └─ VariableDeclarator @2:10
            │        ├─ Identifier "x" [variable:0] @2:16
            │        └─ NullLiteral @2:20
            ├─ test
            │  └─ BinaryExpression (===) @2:28
            │     ├─ Identifier "x" [variable:0] @2:26
            │     └─ NullLiteral @2:32
            └─ body
               └─ BlockStatement @2:40