private static void AppendAsBase32( StringBuilder sb, int value )
{
//// NOTE: code is partially based on:
//// http://www.anotherchris.net/csharp/friendly-unique-id-generation-part-2/#base62
if( sb.NullReference() )
throw new ArgumentNullException().StoreFileLine();
if( value < 0 )
throw new ArgumentOutOfRangeException().Store("value", value);
int remainder = 0;
int quotient = Math.DivRem(value /* dividend */, HashCharacters.Length /* divisor */, out remainder);
if( quotient > 0 )
AppendAsBase32(sb, quotient);
sb.Append(HashCharacters[remainder]);
}