@SuppressWarnings("unchecked") // safe since map is not writable
      ImmutableMap<K, V> kvMap = (ImmutableMap<K, V>) map;
      return kvMap;
    } else if (map instanceof EnumMap) {
      EnumMap<?, ?> enumMap = (EnumMap<?, ?>) map;
      for (Entry<?, ?> entry : enumMap.entrySet()) {
        checkNotNull(entry.getKey());
        checkNotNull(entry.getValue());
      }
      @SuppressWarnings({"unchecked", "rawtypes"})

              @Override
              protected Map<AnEnum, String> create(Entry<AnEnum, String>[] entries) {
                return populate(new EnumMap<AnEnum, String>(AnEnum.class), entries);
              }
            })
        .named("EnumMap")
        .withFeatures(
            MapFeature.GENERAL_PURPOSE,
            MapFeature.ALLOWS_NULL_VALUES,
            MapFeature.RESTRICTS_KEYS,

    private final BinaryOperator<V> mergeFunction;
    @CheckForNull private EnumMap<K, V> map = null;

    EnumMapAccumulator(BinaryOperator<V> mergeFunction) {
      this.mergeFunction = mergeFunction;
    }

    void put(K key, V value) {
      if (map == null) {
        map = new EnumMap<>(singletonMap(key, value));
      } else {
        map.merge(key, value, mergeFunction);
      }

import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Supplier;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Comparator;
import java.util.EnumMap;
import java.util.EnumSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.SortedSet;
import java.util.TreeMap;
import java.util.TreeSet;

import java.math.RoundingMode;
import java.util.EnumMap;
import java.util.EnumSet;
import java.util.Map;
import junit.framework.TestCase;

@GwtIncompatible
public class BigDecimalMathTest extends TestCase {
  private static final class RoundToDoubleTester {
    private final BigDecimal input;
    private final Map<RoundingMode, Double> expectedValues = new EnumMap<>(RoundingMode.class);

              @Override
              protected Map<AnEnum, String> create(Entry<AnEnum, String>[] entries) {
                return populate(new EnumMap<AnEnum, String>(AnEnum.class), entries);
              }
            })
        .named("EnumMap")
        .withFeatures(
            MapFeature.GENERAL_PURPOSE,
            MapFeature.ALLOWS_NULL_VALUES,
            MapFeature.RESTRICTS_KEYS,

    private final BinaryOperator<V> mergeFunction;
    @CheckForNull private EnumMap<K, V> map = null;

    EnumMapAccumulator(BinaryOperator<V> mergeFunction) {
      this.mergeFunction = mergeFunction;
    }

    void put(K key, V value) {
      if (map == null) {
        map = new EnumMap<>(singletonMap(key, value));
      } else {
        map.merge(key, value, mergeFunction);
      }

    }
  }

  private static <K extends Enum<K>, V> ImmutableMap<K, ? extends V> copyOfEnumMap(
      EnumMap<?, ? extends V> original) {
    @SuppressWarnings("unchecked") // the best we could do to make copyOf(Map) compile
    EnumMap<K, V> copy = new EnumMap<>((EnumMap<K, ? extends V>) original);
    for (Entry<K, V> entry : copy.entrySet()) {
      checkEntryNotNull(entry.getKey(), entry.getValue());
    }

import java.math.RoundingMode;
import java.util.EnumMap;
import java.util.EnumSet;
import java.util.Map;
import junit.framework.TestCase;

@GwtIncompatible
public class BigDecimalMathTest extends TestCase {
  private static final class RoundToDoubleTester {
    private final BigDecimal input;
    private final Map<RoundingMode, Double> expectedValues = new EnumMap<>(RoundingMode.class);

    assertEquals(intMap.hashCode(), map.entrySet().hashCode());
    assertEquals(intMap.hashCode(), map.hashCode());
  }

  public void testCopyOfEnumMap() {
    EnumMap<AnEnum, String> map = new EnumMap<>(AnEnum.class);
    map.put(AnEnum.B, "foo");
    map.put(AnEnum.C, "bar");
    assertTrue(ImmutableMap.copyOf(map) instanceof ImmutableEnumMap);
  }

  @J2ktIncompatible