public static <T extends @Nullable Object> T get(
      Iterator<? extends T> iterator, int position, @ParametricNullness T defaultValue) {
    checkNonnegative(position);
    advance(iterator, position);
    return getNext(iterator, defaultValue);
  }

  static void checkNonnegative(int position) {
    if (position < 0) {
      throw new IndexOutOfBoundsException("position (" + position + ") must not be negative");
    }
  }

   * wish to override {@link #lower} to forward to this implementation.
   */
  protected @Nullable E standardLower(@ParametricNullness E e) {
    return Iterators.getNext(headSet(e, false).descendingIterator(), null);
  }

  @Override
  public @Nullable E floor(@ParametricNullness E e) {
    return delegate().floor(e);
  }

  /**

   * wish to override {@link #lower} to forward to this implementation.
   */
  protected @Nullable E standardLower(@ParametricNullness E e) {
    return Iterators.getNext(headSet(e, false).descendingIterator(), null);
  }

  @Override
  public @Nullable E floor(@ParametricNullness E e) {
    return delegate().floor(e);
  }

  /**

        list.addLast("3");
        SLinkedList<String>.Entry e = list.getFirstEntry();
        assertThat(e.getPrevious(), is(nullValue()));
        assertThat(e.getNext().getElement(), is("2"));
        e = list.getLastEntry();
        assertThat(e.getNext(), is(nullValue()));
        assertThat(e.getPrevious().getElement(), is("2"));
        list.getEntry(1).remove();
        assertThat(list.getFirst(), is("1"));

      assertEquals(hashOne, entryOne.getHash());
      assertThat(entryOne.getNext()).isNull();
      assertThat(copyOne.getValue()).isEqualTo(valueOne);

      InternalEntry<Object, Object, ?> copyTwo = segment.copyForTesting(entryTwo, copyOne);
      assertThat(copyTwo.getKey()).isEqualTo(keyTwo);
      assertEquals(hashTwo, copyTwo.getHash());
      assertThat(copyTwo.getNext()).isEqualTo(copyOne);

      assertEquals(hashOne, entryOne.getHash());
      assertThat(entryOne.getNext()).isNull();
      assertThat(copyOne.getValue()).isEqualTo(valueOne);

      InternalEntry<Object, Object, ?> copyTwo = segment.copyForTesting(entryTwo, copyOne);
      assertThat(copyTwo.getKey()).isEqualTo(keyTwo);
      assertEquals(hashTwo, copyTwo.getHash());
      assertThat(copyTwo.getNext()).isEqualTo(copyOne);

        if (CompactHashing.getHashPrefix(entry, mask) == hashPrefix
            && Objects.equals(object, elements[entryIndex])) {
          return false;
        }
        next = CompactHashing.getNext(entry, mask);
        bucketLength++;
      } while (next != UNSET);

      if (bucketLength >= MAX_HASH_BUCKET_LENGTH) {
        return convertToHashFloodingResistantImplementation().add(object);
      }

        if (CompactHashing.getHashPrefix(entry, mask) == hashPrefix
            && Objects.equals(object, elements[entryIndex])) {
          return false;
        }
        next = CompactHashing.getNext(entry, mask);
        bucketLength++;
      } while (next != UNSET);

      if (bucketLength >= MAX_HASH_BUCKET_LENGTH) {
        return convertToHashFloodingResistantImplementation().add(object);
      }

          V oldValue = (V) values[entryIndex];

          values[entryIndex] = value;
          accessEntry(entryIndex);
          return oldValue;
        }
        next = CompactHashing.getNext(entry, mask);
        bucketLength++;
      } while (next != UNSET);

      if (bucketLength >= MAX_HASH_BUCKET_LENGTH) {
        return convertToHashFloodingResistantImplementation().put(key, value);
      }

        assertEquals(mockAndxCommand, testBlock.getNext());
        assertEquals(mockAndxCommand, testBlock.getNextResponse());
    }

    @Test
    @DisplayName("Test constructor without andx command")
    void testConstructorWithoutAndx() {
        testBlock = new TestAndXServerMessageBlock(mockConfig, (byte) 0x25);

        assertNull(testBlock.getAndx());
        assertNull(testBlock.getNext());