code: func (o *DeletePetParams) bindAPIKey(rawData []string, hasKey bool, formats strfmt.Registry) error {
  	if !hasKey {
  		return errors.Required("api_key", "header")
  	}
  	var raw string
  	if len(rawData) > 0 {
  		raw = rawData[len(rawData)-1]
  	}
  
  	// Required: true
  
  	if err := validate.RequiredString("api_key", "header", raw); err != nil {
  		return err
  	}
  
  	o.APIKey = raw
  
  	return nil
  }
docs: // bindAPIKey binds and validates parameter APIKey from header.