(CommandList
  children: [
    (Assignment
      keyword: Assign_None
      pairs: [
        (assign_pair
          lhs: (LhsName name:workdir)
          op: Equal
          rhs: 
            {
              (CommandSubPart
                command_list: 
                  (CommandList
                    children: [
                      (Sentence
                        child: 
                          (Assignment
                            keyword: Assign_None
                            pairs: [(assign_pair lhs:(LhsName name:x) op:Equal rhs:{(1)} spids:[5])]
                            spids: [5]
                          )
                        terminator: <Op_Semi ";">
                      )
                      (C {(pwd)})
                    ]
                  )
                left_token: <Left_CommandSub "$(">
                spids: [4 10]
              )
            }
          spids: [3]
        )
      ]
      spids: [3]
    )
  ]
)