public void TestOneOffEncoding(bool pad)
{
var input = GetData();
long length = 0;
var leftover = 0;
var encoder = new Base64Encoder {
Pad = pad
};
var output = new byte[encoder.RequiredBufferSize(input.Length)];
encoder.ProcessBlock(input, output, ref length, ref leftover);
length = (int)encoder.Finalize(output, length, leftover);
output = output[..(int)length];
