/**
   * Returns a {@code Collector} that accumulates the input elements into a new {@code
   * ImmutableSortedSet}, ordered by the specified comparator.
   *
   * <p>If the elements contain duplicates (according to the comparator), only the first duplicate
   * in encounter order will appear in the result.
   *
   * @since 33.2.0 (available since 21.0 in guava-jre)
   */

   * keys and values are the result of applying the provided mapping functions to the input
   * elements. The generated map is sorted by the specified comparator.
   *
   * <p>If the mapped keys contain duplicates (according to the specified comparator), an {@code
   * IllegalArgumentException} is thrown when the collection operation is performed. (This differs

   *
   * <p>The returned supplier is thread-safe. The delegate's {@code get()} method will be invoked at
   * most once unless the underlying {@code get()} throws an exception. The supplier's serialized
   * form does not contain the cached value, which will be recalculated when {@code get()} is called
   * on the deserialized instance.
   *
   * <p>When the underlying delegate throws an exception then this memoizing supplier will keep

    assertTrue("Heap contains 1", mmHeap.remove(1));
    assertFalse("Heap does not contain 1", mmHeap.contains(1));
    assertTrue("Heap contains 2", mmHeap.remove(2));
    assertEquals(0, mmHeap.size());
    assertFalse("Heap does not contain anything", mmHeap.contains(1));
    assertFalse("Heap does not contain anything", mmHeap.remove(2));
  }

  public void testIteratorPastEndException() {

  /**
   * Returns a {@code Collector} that accumulates the input elements into a new {@code
   * ImmutableSortedSet}, ordered by the specified comparator.
   *
   * <p>If the elements contain duplicates (according to the comparator), only the first duplicate
   * in encounter order will appear in the result.
   *
   * @since 21.0
   */

   *
   * <p>This implementation is highly efficient when {@code elements} is itself a {@link Multiset}.
   *
   * @param elements the elements that the multiset should contain
   */
  public static <E extends @Nullable Object> HashMultiset<E> create(
      Iterable<? extends E> elements) {
    HashMultiset<E> multiset = create(Multisets.inferDistinctElements(elements));

      }

      @Override
      public boolean contains(@CheckForNull Object element) {
        return set1.contains(element) && !set2.contains(element);
      }
    };
  }

  /**
   * Returns an unmodifiable <b>view</b> of the symmetric difference of two sets. The returned set
   * contains all elements that are contained in either {@code set1} or {@code set2} but not in

       * we're copying into a `contents` array whose type allows it to contain nulls. Still, it's
       * worth noting that we promise not to put nulls into the array in the first `size` elements.
       * We uphold that promise here because our callers promise that `elements` will not contain
       * nulls in its first `n` elements.
       */
      System.arraycopy(elements, 0, contents, size, n);

import java.util.Set;
import javax.annotation.CheckForNull;

/**
 * An immutable object that may contain a non-null reference to another object. Each instance of
 * this type either contains a non-null reference, or contains nothing (in which case we say that
 * the reference is "absent"); it is never said to "contain {@code null}".
 *
 * <p>A non-null {@code Optional<T>} reference can be used as a replacement for a nullable {@code T}

   * whose elements are the result of applying {@code elementFunction} to the inputs, with counts
   * equal to the result of applying {@code countFunction} to the inputs.
   *
   * <p>If the mapped elements contain duplicates (according to {@code comparator}), the first
   * occurrence in encounter order appears in the resulting multiset, with count equal to the sum of