vlib/v/checker/tests/alias_map_unknown_op_overloading_err.vv:19:10: error: undefined operation `Map` - `Map`
   17 |     mut a := new_map()
   18 |     b := new_map()
   19 |     println(a - b)
      |             ~~~~~
   20 |     a -= b
   21 | }
vlib/v/checker/tests/alias_map_unknown_op_overloading_err.vv:20:7: error: undefined operation `Map` - `Map`
   18 |     b := new_map()
   19 |     println(a - b)
   20 |     a -= b
      |       ~~
   21 | }
