public interface IAuthorService { void AddAuthor(string name); } public class AuthorService : IAuthorService { public void AddAuthor(string name) { // Logic to add a new author here } }In this example, the AddAuthor method takes a string parameter called name, which represents the name of the author you want to add. The method can be implemented to add the author's name to a database, or to a list of authors. The package library for this code may vary depending on the specific implementation of the IAuthorService interface. It could be a custom library developed in-house or a third-party library that provides interfaces for other functionality in addition to those related to adding authors.