this.stack = new ArrayDeque<>();
      stack.addLast(singletonIterator(checkNotNull(root)));
    }

    @Override
    public boolean hasNext() {
      return !stack.isEmpty();
    }

    @Override
    public T next() {
      Iterator<T> itr = stack.getLast(); // throws NSEE if empty
      T result = checkNotNull(itr.next());
      if (!itr.hasNext()) {
        stack.removeLast();
      }

public class FloatArrayAsListTest extends TestCase {

  private static List<Float> asList(Float[] values) {
    float[] temp = new float[values.length];
    for (int i = 0; i < values.length; i++) {
      temp[i] = checkNotNull(values[i]); // checkNotNull for GWT (do not optimize).
    }
    return Floats.asList(temp);
  }

  @J2ktIncompatible
  @GwtIncompatible // suite
  public static Test suite() {

        /* userPassedSupplier= */ false);
  }

  private static <T extends Throwable> T doAssertThrows(
      Class<T> expectedThrowable, ThrowingSupplier supplier, boolean userPassedSupplier) {
    checkNotNull(expectedThrowable);
    checkNotNull(supplier);
    Predicate<Throwable> predicate = INSTANCE_OF.get(expectedThrowable);
    if (predicate == null) {
      throw new IllegalArgumentException(
          expectedThrowable

public class FloatArrayAsListTest extends TestCase {

  private static List<Float> asList(Float[] values) {
    float[] temp = new float[values.length];
    for (int i = 0; i < values.length; i++) {
      temp[i] = checkNotNull(values[i]); // checkNotNull for GWT (do not optimize).
    }
    return Floats.asList(temp);
  }

  @J2ktIncompatible
  @GwtIncompatible // suite
  public static Test suite() {

public class IntArrayAsListTest extends TestCase {

  private static List<Integer> asList(Integer[] values) {
    int[] temp = new int[values.length];
    for (int i = 0; i < values.length; i++) {
      temp[i] = checkNotNull(values[i]); // checkNotNull for GWT (do not optimize).
    }
    return Ints.asList(temp);
  }

  @J2ktIncompatible
  @GwtIncompatible // suite
  public static Test suite() {

   * new entry with those values.
   */
  static <R, C, V> Cell<R, C, V> cellOf(R rowKey, C columnKey, V value) {
    return immutableCell(
        checkNotNull(rowKey, "rowKey"),
        checkNotNull(columnKey, "columnKey"),
        checkNotNull(value, "value"));
  }

  /**
   * A builder for creating immutable table instances, especially {@code public static final} tables
   * ("constant tables"). Example:

  static <E> InvalidatableSet<E> of(
      Set<E> delegate, Supplier<Boolean> validator, Supplier<String> errorMessage) {
    return new InvalidatableSet<>(
        checkNotNull(delegate), checkNotNull(validator), checkNotNull(errorMessage));
  }

  @Override
  protected Set<E> delegate() {
    validate();
    return delegate;
  }

  private InvalidatableSet(

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect;

import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.collect.CollectPreconditions.checkNonnegative;

import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Supplier;
import java.io.Serializable;

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect;

import static com.google.common.base.Preconditions.checkNotNull;
import static com.google.common.collect.CollectPreconditions.checkNonnegative;

import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Supplier;
import java.io.Serializable;

      backingMap.put(rowKey, map);
    }
    return map;
  }

  @CanIgnoreReturnValue
  @Override
  public @Nullable V put(R rowKey, C columnKey, V value) {
    checkNotNull(rowKey);
    checkNotNull(columnKey);
    checkNotNull(value);
    return getOrCreate(rowKey).put(columnKey, value);
  }

  @CanIgnoreReturnValue
  @Override