code: func (c *Converter) RegisterIgnoredConversion(from, to interface{}) error {
  	typeFrom := reflect.TypeOf(from)
  	typeTo := reflect.TypeOf(to)
  	if reflect.TypeOf(from).Kind() != reflect.Ptr {
  		return fmt.Errorf("expected pointer arg for 'from' param 0, got: %v", typeFrom)
  	}
  	if typeTo.Kind() != reflect.Ptr {
  		return fmt.Errorf("expected pointer arg for 'to' param 1, got: %v", typeTo)
  	}
  	c.ignoredConversions[typePair{typeFrom.Elem(), typeTo.Elem()}] = struct{}{}
  	return nil
  }
docs: // RegisterIgnoredConversion registers a "no-op" for conversion, where any requested
  // conversion between from and to is ignored.