code: func (o *PetstoreAPI) Validate() error {
  	var unregistered []string
  
  	if o.JSONConsumer == nil {
  		unregistered = append(unregistered, "JSONConsumer")
  	}
  
  	if o.JSONProducer == nil {
  		unregistered = append(unregistered, "JSONProducer")
  	}
  
  	if o.RolesAuth == nil {
  		unregistered = append(unregistered, "XAuthRolesAuth")
  	}
  
  	if o.StoreInventoryGetHandler == nil {
  		unregistered = append(unregistered, "store.InventoryGetHandler")
  	}
  
  	if o.StoreOrderCreateHandler == nil {
  		unregistered = append(unregistered, "store.OrderCreateHandler")
  	}
  
  	if o.StoreOrderDeleteHandler == nil {
  		unregistered = append(unregistered, "store.OrderDeleteHandler")
  	}
  
  	if o.StoreOrderGetHandler == nil {
  		unregistered = append(unregistered, "store.OrderGetHandler")
  	}
  
  	if o.PetPetCreateHandler == nil {
  		unregistered = append(unregistered, "pet.PetCreateHandler")
  	}
  
  	if o.PetPetDeleteHandler == nil {
  		unregistered = append(unregistered, "pet.PetDeleteHandler")
  	}
  
  	if o.PetPetGetHandler == nil {
  		unregistered = append(unregistered, "pet.PetGetHandler")
  	}
  
  	if o.PetPetListHandler == nil {
  		unregistered = append(unregistered, "pet.PetListHandler")
  	}
  
  	if o.PetPetUpdateHandler == nil {
  		unregistered = append(unregistered, "pet.PetUpdateHandler")
  	}
  
  	if o.PetPetUploadImageHandler == nil {
  		unregistered = append(unregistered, "pet.PetUploadImageHandler")
  	}
  
  	if len(unregistered) > 0 {
  		return fmt.Errorf("missing registration: %s", strings.Join(unregistered, ", "))
  	}
  
  	return nil
  }
docs: // Validate validates the registrations in the PetstoreAPI