question: private static void encode ( int tag , int length , StringBuilder buffer ) { if ( tag == PATTERN_ISO_ZONE && length >= 4 ) { throw new IllegalArgumentException ( "invalid ISO 8601 format: length=" + length ) ; } if ( length < 255 ) { buffer . append ( ( char ) ( tag << 8 | length ) ) ; } else { buffer . append ( ( char ) ( ( tag << 8 ) | 0xff ) ) ; buffer . append ( ( char ) ( length > > > 16 ) ) ; buffer . append ( ( char ) ( length & 0xffff ) ) ; } }
target:  Encodes the given tag and length and puts encoded char(s) into buffer.