(command.CommandList
  children: [
    (command.AndOr
      ops: [Id.Op_DAmp]
      children: [
        (command.DBracket
          expr: 
            (bool_expr.Unary
              op_id: Id.BoolUnary_z
              child: {(DQ ($ Id.VSub_DollarName '$BALLS_CONFIG'))}
            )
        )
        (command.ShAssignment
          pairs: [
            (assign_pair
              lhs: (sh_lhs_expr.Name name:BALLS_CONFIG)
              op: assign_op.Equal
              rhs: {($ Id.VSub_DollarName '$PWD') <'/config.sh'>}
              spids: [18]
            )
          ]
        )
      ]
    )
    (C {<balls>} {<route>} {($ Id.VSub_DollarName '$BALLS_CONFIG')})
  ]
)