// The suppression also covers the cast to E[], discussed below.
  // In the backport, we don't have those cases and thus don't need this suppression.
  // We keep it to minimize diffs.
  @SuppressWarnings("unchecked")
  public static <E> ImmutableSet<E> copyOf(Collection<? extends E> elements) {
    /*
     * TODO(lowasser): consider checking for ImmutableAsList here

     * ImmutableSortedSet#orderedBy}.
     */
    /*
     * TODO(cpovirk): use Object[] instead of E[] in the mainline? (The backport is different and
     * doesn't need this suppression, but we keep it to minimize diffs.) Generally be more clear
     * about when we have an Object[] vs. a Comparable[] or other array type in internalArray? If we
     * used Object[], we might be able to optimize toArray() to use clone() sometimes. (See

     * ImmutableSortedSet#orderedBy}.
     */
    /*
     * TODO(cpovirk): use Object[] instead of E[] in the mainline? (The backport is different and
     * doesn't need this suppression, but we keep it to minimize diffs.) Generally be more clear
     * about when we have an Object[] vs. a Comparable[] or other array type in internalArray? If we
     * used Object[], we might be able to optimize toArray() to use clone() sometimes. (See

  // The suppression also covers the cast to E[], discussed below.
  // In the backport, we don't have those cases and thus don't need this suppression.
  // We keep it to minimize diffs.
  @SuppressWarnings("unchecked")
  public static <E> ImmutableSet<E> copyOf(Collection<? extends E> elements) {
    /*
     * TODO(lowasser): consider checking for ImmutableAsList here

             * corresponds to the least significant nonzero byte in lw ^ rw, since lw and rw are
             * little-endian. Long.numberOfTrailingZeros(diff) tells us the least significant
             * nonzero bit, and zeroing out the first three bits of L.nTZ gives us the shift to get
             * that least significant nonzero byte.
             */

            // roundCeiling is 2^63-1.
            deltaToCeiling++;
          }

          int diff = Longs.compare(deltaToFloor, deltaToCeiling);
          if (diff < 0) { // closer to floor
            return roundFloorAsDouble;
          } else if (diff > 0) { // closer to ceiling
            return roundCeilingAsDouble;
          }

    Multiset<String> ms2 = HashMultiset.create(Arrays.asList("a", "b", "b", "b"));
    Multiset<String> diff = Multisets.difference(ms1, ms2);
    assertThat(diff).contains("a");
    assertEquals(0, diff.count("b"));
    assertEquals(1, diff.count("a"));
    assertFalse(diff.contains("b"));
    assertTrue(diff.contains("a"));
  }

  public void testDifferenceEmptyNonempty() {

    Multiset<String> ms2 = HashMultiset.create(Arrays.asList("a", "b", "b", "b"));
    Multiset<String> diff = Multisets.difference(ms1, ms2);
    assertThat(diff).contains("a");
    assertEquals(0, diff.count("b"));
    assertEquals(1, diff.count("a"));
    assertFalse(diff.contains("b"));
    assertTrue(diff.contains("a"));
  }

  public void testDifferenceEmptyNonempty() {