private string MakeMask(long bit, int size)
{
StringBuilder b = new StringBuilder();
b.Append("0x");
//size * 8 - bit-1 // hvis det er big-endian
string hexValue = (1 << (int)bit).ToString("x");
for (int i = 0; i < size*2-hexValue.Length; i++)
b.Append("0");
b.Append(hexValue);
return b.ToString();
}