return (Optional<T>) INSTANCE;
  }

  private Absent() {}

  @Override
  public boolean isPresent() {
    return false;
  }

  @Override
  public T get() {
    throw new IllegalStateException("Optional.get() cannot be called on an absent value");
  }

  @Override
  public T or(T defaultValue) {
    return checkNotNull(defaultValue, "use Optional.orNull() instead of Optional.or(null)");

    expectAdded(e0());
  }

  @CollectionFeature.Require(absent = SUPPORTS_ADD)
  @CollectionSize.Require(absent = ZERO)
  /*
   * absent = ZERO isn't required, since unmodList.add() must
   * throw regardless, but it keeps the method name accurate.
   */
  public void testAdd_unsupportedPresent() {
    assertThrows(UnsupportedOperationException.class, () -> getList().add(e0()));
  }

      case NEXT_HIGHER:
        assertEquals(nextHigherIndex, answer);
        return;
      case INVERTED_INSERTION_INDEX:
        assertEquals(-1 - nextHigherIndex, answer);
        return;
    }
    throw new AssertionError();
  }

  public void testWithoutDups() {
    for (KeyPresentBehavior presentBehavior : KeyPresentBehavior.values()) {
      for (KeyAbsentBehavior absentBehavior : KeyAbsentBehavior.values()) {

  private static final DontCompareMe DONT_COMPARE_ME = new DontCompareMe();

  private static class DontCompareMe implements Comparable<DontCompareMe> {
    @Override
    public int compareTo(DontCompareMe o) {
      throw new AssertionFailedError();
    }
  }

  @SuppressWarnings({"deprecation", "InlineMeInliner"}) // test of a deprecated method
  public void testCompareBooleans() {
    assertThat(
            ComparisonChain.start()

    }

    @Override
    public Indexed<T> next() {
        return new Indexed<>(iterator.next(), index++);
    }

    @Override
    public void remove() {
        throw new ClUnsupportedOperationException("remove");
    }

        for (final String dialect : this.dialects) {
            bos.write(0x02);
            try {
                bos.write(Strings.getASCIIBytes(dialect));
            } catch (final IOException e) {
                throw new RuntimeCIFSException(e);
            }
            bos.write(0x0);
        }

        System.arraycopy(bos.toByteArray(), 0, dst, dstIndex, bos.size());
        return bos.size();
    }

    @Override

  }

  private static final Object IGNORE_ME =
      new Object() {
        @Override
        public String toString() {
          throw new AssertionFailedError();
        }
      };

  private static final String FORMAT = "I ate %s pies.";

  private static void checkMessage(Exception e) {
    assertThat(e).hasMessageThat().isEqualTo("I ate 5 pies.");

      assertEquals(200, response.code)
      assertEquals("h3", response.negotiatedProtocol)
      assertTrue(response.content.contains("Disallow"))
    } catch (ee: ExecutionException) {
      throw ee.cause?.cause ?: ee.cause!!
    }
  }

  data class Response(
    val code: Int,
    val negotiatedProtocol: String,
    val content: String,
  )

  private fun execute(

 * should use the type safe {@link #putInstance}.
 *
 * <p>Also, if caller suppresses unchecked warnings and passes in an {@code Iterable<String>} for
 * type {@code Iterable<Integer>}, the map won't be able to detect and throw type error.
 *
 * <p>Like any other {@code Map<Class, Object>}, this map may contain entries for primitive types,
 * and a primitive type and its corresponding wrapper type may map to different values.
 *

 * should use the type safe {@link #putInstance}.
 *
 * <p>Also, if caller suppresses unchecked warnings and passes in an {@code Iterable<String>} for
 * type {@code Iterable<Integer>}, the map won't be able to detect and throw type error.
 *
 * <p>Like any other {@code Map<Class, Object>}, this map may contain entries for primitive types,
 * and a primitive type and its corresponding wrapper type may map to different values.
 *