it('should forward from `Unit<*>` to `Unit<void>`', () => {
    const from = createEvent<string>()
    const to = createEvent<void>()

    forward({from, to}) // <-- NOW FIXED
...

const str = createEvent<string>()
const strOrNum = createEvent<string | number>()

// TS v3.5.3 (current version in effector repo)
//
// Produces an error:
//
// Type 'Event<string | number>' is not assignable to type 'Unit<string>'.
//     ...
forward({
  from: strOrNum,
  to: str
})

// TS v3.6.3 (current stable TS version)
//
// Produces an error:
//
// No overload matches this call.
//     ...
forward({
  from: strOrNum,
  to: str
})