public void SetAnnotation_should_be_able_to_add_new_annotations()
{
builder.SetAnnotation("k1", "v1");
builder.SetAnnotation("k2", "v2");
builder.SetAnnotation("k3", "v3");
builder.CurrentSpan.Annotations.Keys.Should().Contain(new[] { "k1", "k2", "k3" });
}