gistfile1.txt

```nim
type
  InterfaceVTableAnimal = object
    <0>say: proc (this: RootRef): string {.nimcall.}
    <1>test2: proc (this: RootRef) {.nimcall.}

type
  Animal = Interface[InterfaceVTableAnimal]
proc initVTable(t: var InterfaceVTableAnimal; TIfaceUnpackedThis#: typedesc) =
  mixin say
  mixin test2
  t.`<0>say` = proc (this: RootRef): string =
    var ifaceUnpackedThis#: TIfaceUnpackedThis#
    unpackObj(this, ifaceUnpackedThis#)
    forceReturnValue(string,
                     checkRequiredMethod(say(ifaceUnpackedThis#), Animal))
  t.`<1>test2` = proc (this: RootRef) =
    var ifaceUnpackedThis#: TIfaceUnpackedThis#
    unpackObj(this, ifaceUnpackedThis#)
    forceReturnValue(void,
                     checkRequiredMethod(test2(ifaceUnpackedThis#), Animal))

proc say(this: Animal): string {.inline, stackTrace: off.} =
  this.private_vTable.`<0>say`(this.private_obj)

proc test2(this: Animal) {.inline, stackTrace: off.} =
  this.private_vTable.`<1>test2`(this.private_obj)

converter toAnimal[T: ref](a`gensym4: T): Animal {.inline.} =
  to(a`gensym4, Animal)

registerInterfaceDecl(Animal):
  proc say(): string
  proc test2()
do:
  t.`<0>say` = proc (this: RootRef): string =
    var ifaceUnpackedThis#: TIfaceUnpackedThis#
    unpackObj(this, ifaceUnpackedThis#)
    forceReturnValue(string,
                     checkRequiredMethod(say(ifaceUnpackedThis#), Animal))
  t.`<1>test2` = proc (this: RootRef) =
    var ifaceUnpackedThis#: TIfaceUnpackedThis#
    unpackObj(this, ifaceUnpackedThis#)
    forceReturnValue(void,
                     checkRequiredMethod(test2(ifaceUnpackedThis#), Animal))
```