core/src/main/java/com/orientechnologies/orient/core/storage/cache/chm/FrequencySketch.java
private void reset() {
    int count = 0;
    for (int i = 0; i < table.length; i++) {
      count += Long.bitCount(table[i] & ONE_MASK);
      table[i] = (table[i] >>> 1) & RESET_MASK;
    }
    size = (size >>> 1) - (count >>> 2);
  }
private void reset() {
    int count = 0;
    for (int i = 0; i < table.length; i++) {
      count += Long.bitCount(table[i] & ONE_MASK);
      table[i] = (table[i] >>> 1) & RESET_MASK;
    }
    size = (size >>> 1) - (count >>> 2);
  }
Reduces every counter by half of its original value.