ProgramNode(0...14)(
  [],
  StatementsNode(0...14)(
    [StringConcatNode(0...14)(
       InterpolatedStringNode(0...8)(
         (0...1),
         [StringNode(1...4)(nil, (1...4), nil, "foo"),
          EmbeddedVariableNode(4...7)(
            (4...5),
            InstanceVariableReadNode(5...7)()
          )],
         (7...8)
       ),
       StringNode(9...14)((9...10), (10...13), (13...14), "bar")
     )]
  )
)
