public static unsafe void GetUtf16SpanFromSBytePointerTest()
    {
        Assert.That(() => MarshalUtilities.GetUtf16Span(null, -1).ToArray(),
                    Is.EqualTo(Array.Empty <ushort>())
                    );

        fixed(ushort *source = Array.Empty <ushort>())
        {
            var pSource = source;

            Assert.That(() => MarshalUtilities.GetUtf16Span(pSource, -1).ToArray(),
                        Is.EqualTo(Array.Empty <ushort>())
                        );
        }

        fixed(ushort *source = new ushort[] { 'A', 'B', 'C' })
        {
            var pSource = source;

            Assert.That(() => MarshalUtilities.GetUtf16Span(pSource, -1).ToArray(),
                        Is.EqualTo(new ushort[] { 'A', 'B', 'C' })
                        );

            Assert.That(() => MarshalUtilities.GetUtf16Span(pSource, 2).ToArray(),
                        Is.EqualTo(new ushort[] { 'A', 'B' })
                        );
        }
    }
    public static void GetUtf16SpanFromStringTest()
    {
        Assert.That(() => MarshalUtilities.GetUtf16Span(null).ToArray(),
                    Is.EqualTo(Array.Empty <ushort>())
                    );

        Assert.That(() => MarshalUtilities.GetUtf16Span(string.Empty).ToArray(),
                    Is.EqualTo(Array.Empty <ushort>())
                    );

        Assert.That(() => MarshalUtilities.GetUtf16Span("ABC").ToArray(),
                    Is.EqualTo(new ushort[] { 'A', 'B', 'C' })
                    );
    }
    public static unsafe void GetUtf16SpanFromSByteReferenceTest()
    {
        Assert.That(() => MarshalUtilities.GetUtf16Span(UnsafeUtilities.NullRef <ushort>(), -1).ToArray(),
                    Is.EqualTo(Array.Empty <ushort>())
                    );

        var source = new ushort[] { 'A', 'B', 'C' };

        Assert.That(() => MarshalUtilities.GetUtf16Span(in source[0], -1).ToArray(),
                    Is.EqualTo(new ushort[] { 'A', 'B', 'C' })
                    );

        Assert.That(() => MarshalUtilities.GetUtf16Span(in source[0], 2).ToArray(),
                    Is.EqualTo(new ushort[] { 'A', 'B' })
                    );
    }