}

  private static final class SupplierComposition<
          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);
    }

  }

  private static final class SupplierComposition<
          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);
    }

    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);

    builder.weigher(constantWeigher(42)).build(CacheLoader.from(Suppliers.ofInstance(null)));
  }

  @SuppressWarnings("ReturnValueIgnored")
  public void testMaximumWeight_withoutWeigher() {
    CacheBuilder<Object, Object> builder = CacheBuilder.from(parse("maximumWeight=9000"));
    assertThrows(
        IllegalStateException.class,
        () -> builder.build(CacheLoader.from(Suppliers.ofInstance(null))));
  }

import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.base.Suppliers;
import com.google.common.collect.ImmutableList;
import com.google.common.testing.ClassSanityTester;
import com.google.common.util.concurrent.MoreExecutors.Application;
import java.lang.Thread.State;

import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.base.Suppliers;
import com.google.common.collect.ImmutableList;
import com.google.common.testing.ClassSanityTester;
import com.google.common.util.concurrent.MoreExecutors.Application;
import java.lang.Thread.State;

    }
  }

  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))

    }
  }

  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))

   * obtained from the passed supplier.
   *
   * @param stripes the minimum number of stripes (locks) required
   * @param supplier a {@code Supplier<L>} object to obtain locks from
   * @return a new {@code Striped<L>}
   * @since 33.5.0
   */
  public static <L> Striped<L> custom(int stripes, Supplier<L> supplier) {
    return new CompactStriped<>(stripes, supplier);
  }

  /**

        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);