checkNotNull(cell.getValue(), "value");
        @SuppressWarnings("unchecked") // all supported methods are covariant
        Cell<R, C, V> immutableCell = (Cell<R, C, V>) cell;
        cells.add(immutableCell);
      } else {
        put(cell.getRowKey(), cell.getColumnKey(), cell.getValue());
      }
      return this;
    }

    /**

   * row, and so on.
   *
   * <p>Each cell is an immutable snapshot of a row key / column key / value mapping, taken at the
   * time the cell is returned by a method call to the set or its iterator.
   */
  @Override
  public Set<Cell<R, C, V>> cellSet() {
    return super.cellSet();
  }

  @Override
  Iterator<Cell<R, C, V>> cellIterator() {
    return new CellIterator();
  }

  public void testImmutableEntrySerialization() {
    Cell<String, Integer, Character> entry = Tables.immutableCell("foo", 1, 'a');
    SerializableTester.reserializeAndAssert(entry);
  }

  public void testImmutableEntryToString() {
    Cell<String, Integer, Character> entry = Tables.immutableCell("foo", 1, 'a');
    assertEquals("(foo,1)=a", entry.toString());

    Cell<@Nullable String, @Nullable Integer, @Nullable Character> nullEntry =

      }
    }
  }

  public void testKnownUtf8Hashing() {
    for (Cell<HashFunction, String, String> cell : KNOWN_HASHES.cellSet()) {
      HashFunction func = cell.getRowKey();
      String input = cell.getColumnKey();
      String expected = cell.getValue();
      assertEquals(
          String.format(Locale.ROOT, "Known hash for hash(%s, UTF_8) failed", input),

    table = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');
    Cell<String, Integer, Character> cell = table.cellSet().iterator().next();
    assertEquals(Tables.immutableCell("foo", 1, 'a'), cell);
    assertEquals((Character) 'a', table.put("foo", 1, 'd'));
    assertEquals(Tables.immutableCell("foo", 1, 'd'), cell);
  }

  public void testRowMissing() {

    table = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');
    Cell<String, Integer, Character> cell = table.cellSet().iterator().next();
    assertEquals(Tables.immutableCell("foo", 1, 'a'), cell);
    assertEquals((Character) 'a', table.put("foo", 1, 'd'));
    assertEquals(Tables.immutableCell("foo", 1, 'd'), cell);
  }

  public void testRowMissing() {

import com.google.common.annotations.GwtCompatible;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * An unhashable object to be used in testing as values in our collections.
 *
 * @author Regina O'Dell
 */
@GwtCompatible
public class UnhashableObject implements Comparable<UnhashableObject> {
  private final int value;

  public UnhashableObject(int value) {
    this.value = value;
  }

  @Override

 * closing streams for you.
 *
 * <p>This package is a part of the open-source <a href="https://github.com/google/guava">Guava</a>
 * library. For more information on Sources and Sinks as well as other features of this package, see
 * <a href="https://github.com/google/guava/wiki/IOExplained">I/O Explained</a> on the Guava wiki.
 *
 * @author Chris Nokleberg
 */
@CheckReturnValue
@ParametersAreNonnullByDefault

 *   <li>{@link Throwables}
 *   <li>{@link Verify}
 * </ul>
 *
 * <h3>The rest</h3>
 *
 * This package also contains some classes with niche use cases (e.g., {@link Utf8} and {@link
 * Defaults}), as well as a number of classes that have been superseded by additions to the JDK.
 */
@CheckReturnValue
@ParametersAreNonnullByDefault
package com.google.common.base;

import com.google.errorprone.annotations.CheckReturnValue;

   *   <li>{@code unsafeReplacement == null}
   * </ul>
   *
   * <p>For performance reasons escapers created by this builder are not Unicode aware and will not
   * validate the well-formedness of their input.
   */
  public static Builder builder() {
    return new Builder();
  }

  /**
   * A builder for simple, fast escapers.
   *