def to_64(number, rounds)
      r = StringIO.new
      rounds.times do |x|
        r.print(SALT_CHARS[number % 64])
        number >>= 6
      end
      return r.string
    end
def to_64(number, rounds)
      r = StringIO.new
      rounds.times do |x|
        r.print(SALT_CHARS[number % 64])
        number >>= 6
      end
      return r.string
    end
Internal: this is not the Base64 encoding, this is the to64()
 method from the apache protable runtime library