docs: public final long getPackedLong() {
          final int lead = getUint8();
          if (lead < 251) return lead;
  
          switch (lead) {
              case 251:
                  return NULL_LENGTH;
              case 252:
                  return getUint16();
              case 253:
                  return getUint24();
              default: /* Must be 254 when here */
                  final long value = getUint32();
                  position += 4; /* ignore other */
                  return value;
          }
      }