code: @Nonnull
      public static SessionValidityInfo decode( @Nonnull final byte[] data ) {
          int idx = 0;
          final int maxInactiveInterval = (int) decodeNum( data, idx, 4 );
          final long lastAccessedTime = decodeNum( data, idx += 4, 8 );
          final long thisAccessedTime = decodeNum( data, idx += 8, 8 );
          return new SessionValidityInfo( maxInactiveInterval, lastAccessedTime, thisAccessedTime );
      }
docs: Decode the given byte[] that previously was created via {@link #encode(long, long, long)}.