public async Task EnsuresArgumentsNotNull()
{
var connection = Substitute.For<IApiConnection>();
var client = new IssueCommentsClient(connection);
await AssertEx.Throws<ArgumentNullException>(async () => await client.Update(null, "name", 42, "title"));
await AssertEx.Throws<ArgumentException>(async () => await client.Update("", "name", 42, "x"));
await AssertEx.Throws<ArgumentNullException>(async () => await client.Update("owner", null, 42, "x"));
await AssertEx.Throws<ArgumentException>(async () => await client.Update("owner", "", 42, "x"));
await AssertEx.Throws<ArgumentNullException>(async () => await client.Update("owner", "name", 42, null));
}