public void DecodeHex()
{
StringOperators.DecodeHex(null).Should().BeNull();
StringOperators.DecodeHex("").Should().Be("");
StringOperators.DecodeHex("45776f7574").Should().Be("Ewout");
StringOperators.DecodeHex("e7bc96e7a081e696b9e5bc8f").Should().Be("编码方式");
StringOperators.FpDecode("45776f7574", "hex").Should().Be("Ewout");
}