code: func (f *defaultFormats) DelByFormat(strfmt Format) bool {
  	f.Lock()
  	defer f.Unlock()
  
  	tpe := reflect.TypeOf(strfmt)
  	if tpe.Kind() == reflect.Ptr {
  		tpe = tpe.Elem()
  	}
  
  	for i, v := range f.data {
  		if v.Type == tpe {
  			f.data[i] = knownFormat{} // release
  			f.data = append(f.data[:i], f.data[i+1:]...)
  			return true
  		}
  	}
  	return false
  }
docs: // DelByType removes the specified format, returns true when an item was actually removed