vlib/v/checker/tests/free_method_errors.vv:3:5: error: `.free()` methods should be defined on either a `(mut x &Error1)`, or a `(x &Error1)` receiver
    1 | struct Error1 {}
    2 | 
    3 | fn (a Error1) free() {}
      |     ~~~~~~~~
    4 | 
    5 | struct Error2 {}
vlib/v/checker/tests/free_method_errors.vv:7:23: error: `.free()` methods should not have a return type
    5 | struct Error2 {}
    6 | 
    7 | fn (a &Error2) free() f64 {}
      |                       ~~~
    8 | 
    9 | struct Error3 {}
vlib/v/checker/tests/free_method_errors.vv:11:1: error: `.free()` methods should have 0 arguments
    9 | struct Error3 {}
   10 | 
   11 | fn (a &Error3) free(x int) {}
      | ~~~~~~~~~~~~~~~~~~~~~~~~~~
   12 | 
   13 | struct Ok {}
