ProgramNode(0...24)(
  [],
  StatementsNode(0...24)(
    [UndefNode(0...9)([SymbolNode(6...9)(nil, (6...9), nil, "foo")], (0...5)),
     UndefNode(10...24)(
       [SymbolNode(16...19)(nil, (16...19), nil, "foo"),
        SymbolNode(21...24)(nil, (21...24), nil, "bar")],
       (10...15)
     )]
  )
)
