public async Task CompleteAsync_throws_if_called_twice(MockClientStreamWriter <HelloReply> sut)
{
await sut.CompleteAsync();
Assert.That(() => sut.CompleteAsync(), Throws.Exception);
}
public async Task WriteAsync_throws_if_called_after_CompleteAsync(MockClientStreamWriter <HelloReply> sut, HelloReply item)
{
await sut.CompleteAsync();
Assert.That(() => sut.WriteAsync(item), Throws.Exception);
}