Map<C, V> row = safeGet(rowMap(), rowKey);
    return row != null && Maps.safeContainsKey(row, columnKey);
  }

  @Override
  public @Nullable V get(@Nullable Object rowKey, @Nullable Object columnKey) {
    Map<C, V> row = safeGet(rowMap(), rowKey);
    return (row == null) ? null : safeGet(row, columnKey);
  }

  @Override
  public boolean isEmpty() {

import static com.google.common.collect.Maps.asMapEntryIterator;
import static com.google.common.collect.Maps.immutableEntry;
import static com.google.common.collect.Maps.safeContainsKey;
import static com.google.common.collect.Maps.safeGet;
import static com.google.common.collect.NullnessCasts.uncheckedCastNullableTToT;
import static com.google.common.collect.Tables.immutableCell;
import static java.util.Objects.requireNonNull;

    }
  }

  /**
   * Delegates to {@link Map#get}. Returns {@code null} on {@code ClassCastException} and {@code
   * NullPointerException}.
   */
  static <V extends @Nullable Object> @Nullable V safeGet(Map<?, V> map, @Nullable Object key) {
    checkNotNull(map);
    try {
      return map.get(key);
    } catch (ClassCastException | NullPointerException e) {
      return null;
    }
  }

    }
  }

  /**
   * Delegates to {@link Map#get}. Returns {@code null} on {@code ClassCastException} and {@code
   * NullPointerException}.
   */
  static <V extends @Nullable Object> @Nullable V safeGet(Map<?, V> map, @Nullable Object key) {
    checkNotNull(map);
    try {
      return map.get(key);
    } catch (ClassCastException | NullPointerException e) {
      return null;
    }
  }

    public Iterator<K> iterator() {
      return Maps.keyIterator(multimap.entries().iterator());
    }

    @Override
    public int count(@Nullable Object element) {
      Collection<V> values = Maps.safeGet(multimap.asMap(), element);
      return (values == null) ? 0 : values.size();
    }

    @Override
    public int remove(@Nullable Object element, int occurrences) {

    public Iterator<K> iterator() {
      return Maps.keyIterator(multimap.entries().iterator());
    }

    @Override
    public int count(@Nullable Object element) {
      Collection<V> values = Maps.safeGet(multimap.asMap(), element);
      return (values == null) ? 0 : values.size();
    }

    @Override
    public int remove(@Nullable Object element, int occurrences) {