code: public static int getMaxSerializedBytes(final int lgK) {
      checkLgK(lgK);
      if (lgK <= 19) { return empiricalMaxBytes[lgK - 4] + 40; }
      final int k = 1 << lgK;
      return (int) (0.6 * k) + 40; // 0.6 = 4.8 / 8.0
    }
docs: The actual size of a compressed CPC sketch has a small random variance, but the following
  empirically measured size should be large enough for at least 99.9 percent of sketches.
  
  <p>For small values of <i>n</i> the size can be much smaller.
  
  @param lgK the given value of lgK.
  @return the estimated maximum compressed serialized size of a sketch.