static string GetOrAddCachedValue([NotNull] ref string?cache, HeaderDescriptor descriptor, ReadOnlySpan <byte> value)
{
string?lastValue = cache;
if (lastValue is null || !ByteArrayHelpers.EqualsOrdinalAscii(lastValue, value))
{
cache = lastValue = descriptor.GetHeaderValue(value);
}
return(lastValue);
}