* future version of {@code com.google.common.base.Supplier} will be made to <i>extend</i> {@code
 * java.util.function.Supplier}, making conversion code necessary only in one direction. At that
 * time, this interface will be officially discouraged.
 *
 * @author Harry Heymann
 * @since 2.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault

   * words, the new supplier's value will be computed by retrieving the value from {@code supplier},
   * and then applying {@code function} to that value. Note that the resulting supplier will not
   * call {@code supplier} or invoke {@code function} until it is called.
   */
  public static <F extends @Nullable Object, T extends @Nullable Object> Supplier<T> compose(
      Function<? super F, T> function, Supplier<F> supplier) {

  public void testOr_supplier_present() {
    assertEquals("a", Optional.of("a").or(Suppliers.ofInstance("fallback")));
  }

  public void testOr_supplier_absent() {
    assertEquals("fallback", Optional.absent().or(Suppliers.ofInstance("fallback")));
  }

  public void testOr_nullSupplier_absent() {
    Supplier<Object> nullSupplier = (Supplier<Object>) Suppliers.<@Nullable Object>ofInstance(null);

  }

  public static <E extends @Nullable Object> SpliteratorTester<E> of(
      Supplier<Spliterator<E>> spliteratorSupplier) {
    return new SpliteratorTester<>(
        ImmutableSet.of(() -> new GeneralSpliteratorOfObject<>(spliteratorSupplier.get())));
  }

  /**
   * @since 28.1
   */
  public static SpliteratorTester<Integer> ofInt(Supplier<Spliterator.OfInt> spliteratorSupplier) {
    return new SpliteratorTester<>(

          A result(Collector<T, A, R> collector, Iterable<T> inputs) {
        A accum = collector.supplier().get();
        for (T input : inputs) {
          A newAccum = collector.supplier().get();
          collector.accumulator().accept(newAccum, input);
          accum = collector.combiner().apply(accum, newAccum);
        }
        return accum;
      }

import com.google.common.collect.Tables.AbstractCell;
import java.util.ArrayList;
import java.util.List;
import java.util.function.BinaryOperator;
import java.util.function.Function;
import java.util.function.Supplier;
import java.util.stream.Collector;
import org.checkerframework.checker.nullness.qual.Nullable;

/** Collectors utilities for {@code common.collect.Table} internals. */
@GwtCompatible
@ElementTypesAreNonnullByDefault

  public void testOr_supplier_present() {
    assertEquals("a", Optional.of("a").or(Suppliers.ofInstance("fallback")));
  }

  public void testOr_supplier_absent() {
    assertEquals("fallback", Optional.absent().or(Suppliers.ofInstance("fallback")));
  }

  public void testOr_nullSupplier_absent() {
    Supplier<Object> nullSupplier = (Supplier<Object>) Suppliers.<@Nullable Object>ofInstance(null);

@ElementTypesAreNonnullByDefault
public class NewCustomTableTest extends AbstractTableTest<Character> {

  @Override
  protected Table<String, Integer, Character> create(@Nullable Object... data) {
    Supplier<TreeMap<Integer, Character>> factory =
        new Supplier<TreeMap<Integer, Character>>() {
          @Override
          public TreeMap<Integer, Character> get() {
            return Maps.newTreeMap();
          }
        };

   *
   * @throws NullPointerException if this optional's value is absent and the supplier returns {@code
   *     null}
   */
  public abstract T or(Supplier<? extends T> supplier);

  /**
   * Returns the contained instance if it is present; {@code null} otherwise. If the instance is
   * known to be present, use {@link #get()} instead.
   *
   * <p><b>Comparison to {@code java.util.Optional}:</b> this method is equivalent to Java 8's

import java.util.EnumMap;
import java.util.EnumSet;
import java.util.LinkedHashMap;
import java.util.TreeMap;
import java.util.function.BinaryOperator;
import java.util.function.Function;
import java.util.function.Supplier;
import java.util.function.ToIntFunction;
import java.util.stream.Collector;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import javax.annotation.CheckForNull;