(CommandList
  children: [
    (Assignment
      keyword: Assign_None
      pairs: [
        (assign_pair
          lhs: (LhsName name:NUM_NODES)
          op: Equal
          rhs: 
            {
              (BracedVarSub
                token: <VSub_Name NUM_NODES>
                suffix_op: (StringUnary op_id:VTest_ColonHyphen arg_word:{(2)})
                spids: [45 49]
              )
            }
          spids: [44]
        )
      ]
      spids: [44]
    )
  ]
)