}
    };
  }

  private static final String KEY = "puppies";

  ConcurrentMap<String, AtomicInteger> backingMap;
  ConcurrentHashMultiset<String> multiset;

  @SuppressWarnings("unchecked")
  @Override
  protected void setUp() {
    backingMap = mock(ConcurrentMap.class);
    when(backingMap.isEmpty()).thenReturn(true);

    multiset = ConcurrentHashMultiset.create(backingMap);

   * @since 20.0
   */
  public static <E> ConcurrentHashMultiset<E> create(ConcurrentMap<E, AtomicInteger> countMap) {
    checkArgument(countMap.isEmpty(), "the backing map (%s) must be empty", countMap);
    return new ConcurrentHashMultiset<>(countMap);
  }

  private ConcurrentHashMultiset(ConcurrentMap<E, AtomicInteger> countMap) {
    this.countMap = countMap;
  }

  // Query Operations

    // Cache for method lookups: Class -> PropertyName -> MethodInfo
    private static final ConcurrentMap<Class<?>, Map<String, MethodInfo>> METHOD_CACHE = new ConcurrentHashMap<>();

    // Cache for field lookups: Class -> FieldName -> Field
    private static final ConcurrentMap<Class<?>, Map<String, Field>> FIELD_CACHE = new ConcurrentHashMap<>();

    private final ConverterLookup lookup;

import com.google.common.primitives.Ints;
import java.util.List;
import java.util.Random;
import java.util.concurrent.Callable;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.ConcurrentSkipListMap;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Future;

import java.util.SortedSet;
import java.util.TreeMap;
import java.util.TreeSet;
import java.util.UUID;
import java.util.concurrent.BlockingDeque;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.ConcurrentNavigableMap;
import java.util.concurrent.DelayQueue;
import java.util.concurrent.Executor;
import java.util.concurrent.PriorityBlockingQueue;

import java.util.SortedSet;
import java.util.TreeMap;
import java.util.TreeSet;
import java.util.UUID;
import java.util.concurrent.BlockingDeque;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.ConcurrentNavigableMap;
import java.util.concurrent.DelayQueue;
import java.util.concurrent.Executor;
import java.util.concurrent.PriorityBlockingQueue;

import java.util.NavigableSet;
import java.util.Properties;
import java.util.Set;
import java.util.SortedMap;
import java.util.SortedSet;
import java.util.TreeMap;
import java.util.concurrent.ConcurrentMap;
import junit.framework.TestCase;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Unit test for {@code Maps}.
 *
 * @author Kevin Bourrillion

import java.util.NavigableSet;
import java.util.Properties;
import java.util.Set;
import java.util.SortedMap;
import java.util.SortedSet;
import java.util.TreeMap;
import java.util.concurrent.ConcurrentMap;
import junit.framework.TestCase;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Unit test for {@code Maps}.
 *
 * @author Kevin Bourrillion

import java.util.SortedMap;
import java.util.SortedSet;
import java.util.Spliterator;
import java.util.Spliterators;
import java.util.TreeMap;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.function.BiConsumer;
import java.util.function.BiFunction;
import java.util.function.BinaryOperator;
import java.util.function.Consumer;
import java.util.stream.Collector;