!7

static int n = 20000;

p {
  for (int tableSize = 0; tableSize < 100; tableSize += 10) {
    O[] data = arrayOfBlankObjects(tableSize);
    O[] array = new O[n];
    long mem1 = usedMemoryAfterGC();
    for i over array: {
      new HashMap hashMap;
      for (O x : data) hashMap.put(x, x);
      array[i] = hashMap;
    }
    long mem2 = usedMemoryAfterGC();
    double objSize = (mem2-mem1)/(double) l(array);
    int rounded = iround(objSize);
    long f = guessHashMapSize(tableSize);
    print("Hash table size=" + tableSize + ". Approximate object size: " + objSize + " => " + rounded + " bytes. Formula: " + f);
  }
}

Began life as a copy of #1009423