public async Task WriteToPipeWriter()
{
var blist = new BList {
1, 2, "abc"
};
var(reader, writer) = new Pipe();
blist.EncodeTo(writer);
await writer.FlushAsync();
reader.TryRead(out var readResult);
var result = Encoding.UTF8.GetString(readResult.Buffer.First.Span.ToArray());
result.Should().Be("li1ei2e3:abce");
}