F extends @Nullable Object, T extends @Nullable Object>
      implements Supplier<T>, Serializable {
    final Function<? super F, T> function;
    final Supplier<F> supplier;

    SupplierComposition(Function<? super F, T> function, Supplier<F> supplier) {
      this.function = checkNotNull(function);
      this.supplier = checkNotNull(supplier);
    }

    @Override
    @ParametricNullness
    public T get() {

          F extends @Nullable Object, T extends @Nullable Object>
      implements Supplier<T>, Serializable {
    final Function<? super F, T> function;
    final Supplier<F> supplier;

    SupplierComposition(Function<? super F, T> function, Supplier<F> supplier) {
      this.function = checkNotNull(function);
      this.supplier = checkNotNull(supplier);
    }

    @Override
    @ParametricNullness
    public T get() {

        Supplier<Object> supplier = () -> null;

        monitorTarget.append(buf, "testKey", supplier);
        assertEquals("\"testKey\":null", buf.toString());
    }

    // Test append method with Integer value
    @Test
    public void test_append_integerValue() {
        StringBuilder buf = new StringBuilder();
        Supplier<Object> supplier = () -> Integer.valueOf(123);

  }

  private static void assertChecksum(ImmutableSupplier<Checksum> supplier, String input) {
    byte[] bytes = HashTestUtils.ascii(input);

    Checksum checksum = supplier.get();
    checksum.update(bytes, 0, bytes.length);
    long value = checksum.getValue();

    String toString = "name";
    HashFunction func = new ChecksumHashFunction(supplier, 32, toString);
    assertThat(func.toString()).isEqualTo(toString);

      Supplier<Spliterator<E>> spliteratorSupplier) {
    return new SpliteratorTester<>(
        ImmutableSet.of(() -> new GeneralSpliteratorOfObject<>(spliteratorSupplier.get())));
  }

  /**
   * @since 33.4.0 (but since 28.1 in the JRE flavor)
   */
  public static SpliteratorTester<Integer> ofInt(Supplier<Spliterator.OfInt> spliteratorSupplier) {

      Supplier<Spliterator<E>> spliteratorSupplier) {
    return new SpliteratorTester<>(
        ImmutableSet.of(() -> new GeneralSpliteratorOfObject<>(spliteratorSupplier.get())));
  }

  /**
   * @since 28.1 (but only since 33.4.0 in the Android flavor)
   */
  public static SpliteratorTester<Integer> ofInt(Supplier<Spliterator.OfInt> spliteratorSupplier) {

    assertThat(Optional.of("a").or(Suppliers.ofInstance("fallback"))).isEqualTo("a");
  }

  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);

  }

  private static void assertChecksum(ImmutableSupplier<Checksum> supplier, String input) {
    byte[] bytes = HashTestUtils.ascii(input);

    Checksum checksum = supplier.get();
    checksum.update(bytes, 0, bytes.length);
    long value = checksum.getValue();

    String toString = "name";
    HashFunction func = new ChecksumHashFunction(supplier, 32, toString);
    assertThat(func.toString()).isEqualTo(toString);

    }
  }

  public void testForSupplier() {
    Supplier<Integer> supplier = new CountingSupplier();
    Function<@Nullable Object, Integer> function = Functions.forSupplier(supplier);

    assertEquals(1, (int) function.apply(null));
    assertEquals(2, (int) function.apply("foo"));

    new EqualsTester()
        .addEqualityGroup(function, Functions.forSupplier(supplier))

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.base.Supplier;
import com.google.common.base.Suppliers;
import com.google.common.util.concurrent.TestExceptions.SomeCheckedException;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import junit.framework.TestCase;