code: func MustShimLegacyState(legacy *State) *states.State {
  	ret, err := ShimLegacyState(legacy)
  	if err != nil {
  		panic(err)
  	}
  	return ret
  }
docs: // MustShimLegacyState is a wrapper around ShimLegacyState that panics if
  // the conversion does not succeed. This is primarily intended for tests where
  // the given legacy state is an object constructed within the test.