import java.util.Map.Entry;
import java.util.Set;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A {@link Multimap} whose contents will never change, with many other important properties
 * detailed at {@link ImmutableCollection}.
 *
 * <p><b>Warning:</b> avoid <i>direct</i> usage of {@link ImmutableMultimap} as a type (as with

import java.util.stream.Collector;
import java.util.stream.Collectors;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A {@link Map} whose contents will never change, with many other important properties detailed at
 * {@link ImmutableCollection}.
 *
 * <p>See the Guava User Guide article on <a href=
 * "https://github.com/google/guava/wiki/ImmutableCollectionsExplained">immutable collections</a>.
 *

  <properties>
    <!--
    We could override this to change which version we run tests under.
    However, I think that our -Djava.security.manager=allow profile is based on the *Maven* JDK.
    If we want to use overrides here, we should change that profile to also be based on surefire.toolchain.version.
    -->
    <surefire.toolchain.version>${java.specification.version}</surefire.toolchain.version>

  <properties>
    <!--
    We could override this to change which version we run tests under.
    However, I think that our -Djava.security.manager=allow profile is based on the *Maven* JDK.
    If we want to use overrides here, we should change that profile to also be based on surefire.toolchain.version.
    -->
    <surefire.toolchain.version>${java.specification.version}</surefire.toolchain.version>

    assertEquals(1, filtered.size());
    assertTrue(filtered.containsEntry("foo", 1));
    assertTrue(filtered.keySet().retainAll(asList("cat", "dog")));
    assertEquals(0, filtered.size());
  }

  // TODO(jlevy): Many more tests needed.

    assertEquals(1, filtered.size());
    assertTrue(filtered.containsEntry("foo", 1));
    assertTrue(filtered.keySet().retainAll(asList("cat", "dog")));
    assertEquals(0, filtered.size());
  }

  // TODO(jlevy): Many more tests needed.

    expected.addAll(index, elements);
    expectContents(expected);
  }

  /*
   * TODO: if we're testing a list, we could check indexOf(). (Doing it in
   * AbstractListTester isn't enough because many tests that run on lists don't
   * extends AbstractListTester.) We could also iterate over all elements to
   * verify absence
   */
  protected void expectMissing(E... elements) {
    for (E element : elements) {

      backingMap.put(element, new Count(occurrences));
    } else {
      oldCount = frequency.get();
      long newCount = (long) oldCount + (long) occurrences;
      checkArgument(newCount <= Integer.MAX_VALUE, "too many occurrences: %s", newCount);
      frequency.add(occurrences);
    }
    size += occurrences;
    return oldCount;
  }

  @CanIgnoreReturnValue
  @Override

 *
 * <p>This implementation is based on the <a
 * href="http://portal.acm.org/citation.cfm?id=6621">min-max heap</a> developed by Atkinson, et al.
 * Unlike many other double-ended priority queues, it stores elements in a single array, as compact
 * as the traditional heap data structure used in {@link PriorityQueue}.
 *
 * <p>This class is not thread-safe, and does not accept null elements.

    } catch (IndexOutOfBoundsException expected) {
    } catch (IllegalArgumentException expected) {
      /*
       * The subList() docs claim that this should be an
       * IndexOutOfBoundsException, but many JDK implementations throw
       * IllegalArgumentException:
       * http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4506427
       */
    }
  }

  public void testSubList_empty() {