NewAccountController is constructor.

NewBookController is constructor.

NewCategoryController is constructor.

NewErrorController is constructor.

NewFormatController is constructor.

NewHealthController is constructor.

APIError has a error code and a message.

AccountController is a controller for managing user account.

BookController is a controller for managing books.

CategoryController is a controller for managing category data.

ErrorController is a controller for handling errors.

FormatController is a controller for managing format data.

HealthController is a controller returns the current status of this application.