assertThrows(
        ConcurrentModificationException.class,
        () -> {
          Iterator<E> iterator = collection.iterator();
          getList().remove(getNumElements() / 2);
          iterator.next();
        });
  }

  @ListFeature.Require(SUPPORTS_REMOVE_WITH_INDEX)
  @CollectionSize.Require(absent = ZERO)
  public void testRemoveAtIndex_last() {
    runRemoveTest(getNumElements() - 1);
  }

		if offset >= int64(len(block)) {
			// Decrement offset.
			offset -= int64(len(block))
			continue
		}

		// Skip until offset.
		block = block[offset:]

		// Reset the offset for next iteration to read everything
		// from subsequent blocks.
		offset = 0

		// We have written all the blocks, write the last remaining block.
		if write < int64(len(block)) {
			n, err := dst.Write(block[:write])

				// of length j at offset i and ask for
				// Next(k), we get the right bytes.
				buf := NewBuffer(b[0:j])
				n, _ := buf.Read(tmp[0:i])
				if n != i {
					t.Fatalf("Read %d returned %d", i, n)
				}
				bb := buf.Next(k)
				want := k
				if want > j-i {
					want = j - i
				}
				if len(bb) != want {
					t.Fatalf("in %d,%d: len(Next(%d)) == %d", i, j, k, len(bb))
				}

		t.Fatalf("tw.Write: %v", err)
	}
	if err := tw.Close(); err != nil {
		t.Fatalf("tw.Close: %v", err)
	}

	// Read it back.
	tr := NewReader(&b)
	rHdr, err := tr.Next()
	if err != nil {
		t.Fatalf("tr.Next: %v", err)
	}
	if !reflect.DeepEqual(rHdr, hdr) {
		t.Errorf("Header mismatch.\n got %+v\nwant %+v", rHdr, hdr)
	}
	rData, err := io.ReadAll(tr)
	if err != nil {

            break;
          case 1:
            assertThat(network.edgeConnectingOrNull(node, otherNode))
                .isEqualTo(edgesConnecting.iterator().next());
            assertThat(network.hasEdgeConnecting(node, otherNode)).isTrue();
            break;
          default:
            assertThat(network.hasEdgeConnecting(node, otherNode)).isTrue();
            try {

        }

        @Override
        public CommonServerMessageBlockRequest split() {
            return null;
        }

        @Override
        public boolean allowChain(CommonServerMessageBlockRequest next) {
            return true;
        }

        @Override
        public CommonServerMessageBlockRequest createCancel() {
            return null;
        }

        @Override

    return Iterators.pollNext(descendingIterator());
  }

  @ParametricNullness
  protected E standardFirst() {
    return iterator().next();
  }

  @ParametricNullness
  protected E standardLast() {
    return descendingIterator().next();
  }

  @Override
  public NavigableSet<E> descendingSet() {
    return delegate().descendingSet();
  }

  /**

    assertThrows(
        ConcurrentModificationException.class,
        () -> {
          Iterator<E> iterator = collection.iterator();
          getList().add(0, e3());
          iterator.next();
        });
  }

  @ListFeature.Require(absent = SUPPORTS_ADD_WITH_INDEX)
  public void testAddAtIndex_unsupportedNotPresent() {
    assertThrows(UnsupportedOperationException.class, () -> getList().add(0, e3()));

                    Iterator<Item> right = ((ListItem) item).iterator();

                    while (left.hasNext() || right.hasNext()) {
                        Item l = left.hasNext() ? left.next() : null;
                        Item r = right.hasNext() ? right.next() : null;

                        // if this is shorter, then invert the compare and mul with -1

            if (!createIndexResponse.isAcknowledged()) {
                if (logger.isDebugEnabled()) {
                    logger.debug("Could not create next index: {}", indexName);
                }
                throw new SuggesterException("Could not create next index: " + indexName);
            }
            client.admin().cluster().prepareHealth().setWaitForYellowStatus().execute().actionGet(suggestSettings.getClusterTimeout());