private static boolean shouldTrim(int actualUnique, int expectedUnique) {
    return actualUnique < (expectedUnique >> 1) + (expectedUnique >> 2);
  }

  // We use power-of-2 tables, and this is the highest int that's a power of 2
  static final int MAX_TABLE_SIZE = Ints.MAX_POWER_OF_TWO;

  // Represents how tightly we can pack things, as a maximum.
  private static final double DESIRED_LOAD_FACTOR = 0.7;