public void DecompressNull()
    {
        var decompress = new LzwDecompress();
        Action act = () => decompress.Decompress(null, 0, 0, 0);

        act.Should().Throw<ArgumentNullException>();
    }
        private void Decompress(byte[] compressed, byte[] expected)
        {
            var decompress   = new LzwDecompress();
            var uncompressed = decompress.Decompress(compressed, 0, compressed.Length, expected.Length);

            uncompressed.Should().BeEquivalentTo(expected);
        }