code: func decodeGoTypeRef(t design.DataType, required []string, tabs int, private bool) string {
  	mt, ok := t.(*design.MediaTypeDefinition)
  	if ok && mt.IsError() {
  		return "*goa.ErrorResponse"
  	}
  	return codegen.GoTypeRef(t, required, tabs, private)
  }
docs: // decodeGoTypeRef handles the case where the type being decoded is a error response media type.