code: func (k *APIKey) UnmarshalJSON(data []byte) error {
  	type Alias APIKey
  	aux := &struct {
  		Created *string `json:"created,omitempty"`
  		*Alias
  	}{
  		Alias: (*Alias)(k),
  	}
  	if err := json.Unmarshal(data, &aux); err != nil {
  		return err
  	}
  
  	if created, err := time.Parse(createdTimeLayout, *aux.Created); err != nil {
  		return err
  	} else {
  		k.Created = &created
  	}
  
  	return nil
  }
docs: // UnmarshalJSON is a custom method for handling datetime unmarshalling