/// <summary>
/// See <see cref="BaseEncoding.GetDecodeCountWithoutArgumentsValidation(char[], int, int)"/>.
/// </summary>
/// <exception cref="FormatException">input sequence is not a valid base sequence</exception>
protected override int GetDecodeCountWithoutArgumentsValidation(char[] chars, int offset, int length)
{
return(b.DecodeSize(length));
}