code: public static String encode(byte[] in, int off, int len) {
          return inst.encode(in, off, len, null, 0).toString();
      }
docs: Encodes the given bytes into a base-32 string.
  
  @param in
  an array containing the bytes to encode.
  @param off
  the start offset of the data within {@code in}.
  @param len
  the number of bytes to encode.
  
  @return The base-32 string.