vlib/v/checker/tests/generics_undefined_operation_2.vv:23:18: error: mismatched types `INode` and `&INode`
   21 | fn (mut h IHeap[T]) percolateup(hl u64, mut element T) {
   22 |     mut hole := hl
   23 |     for hole > 1 && element < h.array[int(hole / 2)] {
      |                     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   24 |         // ^ Notice that '<' was not defined
   25 |         println("didnt define '<' for the INode")