using System;

using System.Threading.Tasks;

public class Program

{

    public static async Task Main()

    {

        var client = new Gw2Sharp.Gw2Client();

        // successful call

        var items = await client.WebApi.V2.Items.ManyAsync(new[] { 78599, 70093 });     

        foreach (var item in items)

            Console.WriteLine($"{item.Id}: {item.Name}");

        // failel call

        var items2 = await client.WebApi.V2.Items.ManyAsync(new[] { 78599, 70093 });        

​

        foreach (var item in items)

            Console.WriteLine($"{item.Id}: {item.Name}");

    }

}