vlib/v/checker/tests/unimplemented_interface_f.vv:11:13: error: `Cat` incorrectly implements method `speak` of interface `Animal`: expected 2 parameter(s), not 1
    9 | fn main() {
   10 |     mut animals := []Animal{}
   11 |     animals << Cat{}
      |                ~~~~~
   12 | }
Details: main.Animal has `fn speak(x main.Animal, s string)`
         main.Cat has `fn speak(c main.Cat)`