ProgramNode(0...15)(
  [],
  StatementsNode(0...15)(
    [CallNode(0...7)(
       nil,
       nil,
       (0...1),
       nil,
       nil,
       nil,
       BlockNode(1...7)(
         [:a],
         BlockParametersNode(2...6)(
           ParametersNode(3...5)(
             [RequiredParameterNode(3...4)(:a)],
             [],
             [],
             RestParameterNode(4...5)((4...5), nil),
             [],
             nil,
             nil
           ),
           [],
           (2...3),
           (5...6)
         ),
         nil,
         (1...2),
         (6...7)
       ),
       0,
       "x"
     ),
     CallNode(9...15)(
       nil,
       nil,
       (9...10),
       nil,
       nil,
       nil,
       BlockNode(10...15)(
         [:a],
         BlockParametersNode(11...14)(
           ParametersNode(12...13)(
             [RequiredParameterNode(12...13)(:a)],
             [],
             [],
             nil,
             [],
             nil,
             nil
           ),
           [],
           (11...12),
           (13...14)
         ),
         nil,
         (10...11),
         (14...15)
       ),
       0,
       "x"
     )]
  )
)
