* java.util.LinkedHashMap LinkedHashMap} and {@link ImmutableMap#copyOf(Map)} rather than
     * {@code ImmutableMap.Builder}.
     *
     * @since 31.1
     */
    public ImmutableMap<K, V> buildKeepingLast() {
      return build(false);
    }

    @VisibleForTesting // only for testing JDK backed implementation
    ImmutableMap<K, V> buildJdkBacked() {
      checkState(

   * @throws NullPointerException if any key or value in {@code map} is null
   */
  public static <K, V> ImmutableMap<K, V> copyOf(Map<? extends K, ? extends V> map) {
    if ((map instanceof ImmutableMap) && !(map instanceof SortedMap)) {
      @SuppressWarnings("unchecked") // safe since map is not writable
      ImmutableMap<K, V> kvMap = (ImmutableMap<K, V>) map;
      if (!kvMap.isPartialView()) {
        return kvMap;
      }
    }

        ImmutableMap::copyOf);
  }

  @SuppressWarnings("unchecked") // An empty map works for all types.
  public static <K, V> ImmutableMap<K, V> of() {
    return (ImmutableMap<K, V>) RegularImmutableMap.EMPTY;
  }

  public static <K, V> ImmutableMap<K, V> of(K k1, V v1) {
    return ImmutableBiMap.of(k1, v1);
  }

  public static <K, V> ImmutableMap<K, V> of(K k1, V v1, K k2, V v2) {

      this(map, asImmutableList(entries));
    }

    RegularEntrySet(ImmutableMap<K, V> map, ImmutableList<Entry<K, V>> entries) {
      this.map = map;
      this.entries = entries;
    }

    @Override
    ImmutableMap<K, V> map() {
      return map;
    }

    @Override
    @GwtIncompatible // not used in GWT

    this.cellColumnInRowIndices = cellColumnInRowIndices;
    ImmutableMap.Builder<R, ImmutableMap<C, V>> rowBuilder =
        new ImmutableMap.Builder<>(rows.size());
    for (Entry<R, Map<C, V>> row : rows.entrySet()) {
      rowBuilder.put(row.getKey(), ImmutableMap.copyOf(row.getValue()));
    }
    this.rowMap = rowBuilder.buildOrThrow();

    ImmutableMap.Builder<C, ImmutableMap<R, V>> columnBuilder =

@Immutable(containerOf = {"R", "C", "V"})
final class DenseImmutableTable<R, C, V> extends RegularImmutableTable<R, C, V> {
  private final ImmutableMap<R, Integer> rowKeyToIndex;
  private final ImmutableMap<C, Integer> columnKeyToIndex;
  private final ImmutableMap<R, ImmutableMap<C, V>> rowMap;
  private final ImmutableMap<C, ImmutableMap<R, V>> columnMap;

  @SuppressWarnings("Immutable") // We don't modify this after construction.
  private final int[] rowCounts;

  }

  @Override
  public ImmutableMap<R, V> column(C columnKey) {
    checkNotNull(columnKey);
    return containsColumn(columnKey)
        ? ImmutableMap.of(singleRowKey, singleValue)
        : ImmutableMap.of();
  }

  @Override
  public ImmutableMap<C, Map<R, V>> columnMap() {
    return ImmutableMap.of(singleColumnKey, (Map<R, V>) ImmutableMap.of(singleRowKey, singleValue));
  }

  @Override

import org.jspecify.annotations.Nullable;

/**
 * {@code keySet()} implementation for {@link ImmutableMap}.
 *
 * @author Jesse Wilson
 * @author Kevin Bourrillion
 */
@GwtCompatible
final class ImmutableMapKeySet<K, V> extends IndexedImmutableSet<K> {
  private final ImmutableMap<K, V> map;

  ImmutableMapKeySet(ImmutableMap<K, V> map) {
    this.map = map;
  }

  @Override
  public int size() {

    this.cellColumnInRowIndices = cellColumnInRowIndices;
    ImmutableMap.Builder<R, ImmutableMap<C, V>> rowBuilder =
        new ImmutableMap.Builder<>(rows.size());
    for (Entry<R, Map<C, V>> row : rows.entrySet()) {
      rowBuilder.put(row.getKey(), ImmutableMap.copyOf(row.getValue()));
    }
    this.rowMap = rowBuilder.buildOrThrow();

    ImmutableMap.Builder<C, ImmutableMap<R, V>> columnBuilder =

@Immutable(containerOf = {"R", "C", "V"})
final class DenseImmutableTable<R, C, V> extends RegularImmutableTable<R, C, V> {
  private final ImmutableMap<R, Integer> rowKeyToIndex;
  private final ImmutableMap<C, Integer> columnKeyToIndex;
  private final ImmutableMap<R, ImmutableMap<C, V>> rowMap;
  private final ImmutableMap<C, ImmutableMap<R, V>> columnMap;

  @SuppressWarnings("Immutable") // We don't modify this after construction.
  private final int[] rowCounts;