// Replace existing values, if any.
    while (keyValues.hasNext() && newValues.hasNext()) {
      keyValues.next();
      keyValues.set(newValues.next());
    }

    // Remove remaining old values, if any.
    while (keyValues.hasNext()) {
      keyValues.next();
      keyValues.remove();
    }

    // Add remaining new values, if any.
    while (newValues.hasNext()) {

          @Override
          protected void handleLine(String line, String end) {
            lines.add(line + end);
          }
        };
    char[] chars = input.toCharArray();
    int off = 0;
    while (off < chars.length) {
      int len = Math.min(chars.length, off + chunk) - off;
      lineBuf.add(chars, off, len);
      off += len;
    }
    lineBuf.finish();
    return lines;
  }

    assertFullyRead(reader);

    // read in chunks to fixed array
    reader = new CharSequenceReader(charSequence);
    buf = new char[5];
    StringBuilder builder = new StringBuilder();
    int read;
    while ((read = reader.read(buf, 0, buf.length)) != -1) {
      builder.append(buf, 0, read);
    }
    assertEquals(expected, builder.toString());
    assertFullyRead(reader);

    // read all to one CharBuffer

  }

  private static boolean isWellFormedSlowPath(byte[] bytes, int off, int end) {
    int index = off;
    while (true) {
      int byte1;

      // Optimize for interior runs of ASCII bytes.
      do {
        if (index >= end) {
          return true;
        }
      } while ((byte1 = bytes[index++]) >= 0);

      if (byte1 < (byte) 0xE0) {
        // Two-byte form.
        if (index == end) {

      assertThat(graph.edges()).isEmpty();
      AbstractGraphTest.validateGraph(graph);

      while (graph.nodes().size() < NUM_NODES) {
        graph.addNode(gen.nextInt(NODE_POOL_SIZE));
      }
      ArrayList<Integer> nodeList = new ArrayList<>(graph.nodes());
      while (graph.edges().size() < NUM_EDGES) {
        graph.putEdge(getRandomElement(nodeList, gen), getRandomElement(nodeList, gen));
      }

   */
  public static String commonPrefix(CharSequence a, CharSequence b) {
    checkNotNull(a);
    checkNotNull(b);

    int maxPrefixLength = Math.min(a.length(), b.length());
    int p = 0;
    while (p < maxPrefixLength && a.charAt(p) == b.charAt(p)) {
      p++;
    }
    if (validSurrogatePairAt(a, p - 1) || validSurrogatePairAt(b, p - 1)) {
      p--;
    }
    return a.subSequence(0, p).toString();
  }

          } catch (Exception e) { // sneaky checked exception
            log.get().log(Level.SEVERE, "Exception while executing runnable " + task, e);
          } finally {
            task = null;
          }
        }
      } finally {
        // Ensure that if the thread was interrupted at all while processing the task queue, it
        // is returned to the delegate Executor interrupted so that it may handle the

    GraphConnections<N, V> connections = nodeConnections.get(node);
    if (connections == null) {
      return false;
    }

    if (allowsSelfLoops()) {
      // Remove self-loop (if any) first, so we don't get CME while removing incident edges.
      if (connections.removeSuccessor(node) != null) {
        connections.removePredecessor(node);
        --edgeCount;
      }
    }

        checkNotNull(appendable, "appendable");
        checkNotNull(parts, "parts");
        while (parts.hasNext()) {
          Object part = parts.next();
          if (part != null) {
            appendable.append(Joiner.this.toString(part));
            break;
          }
        }
        while (parts.hasNext()) {
          Object part = parts.next();
          if (part != null) {

  }

  /**
   * Returns the {@link Method} instance for {@link #testAddAll_unsupportedNonePresent()} so that
   * tests can suppress it with {@code FeatureSpecificTestSuiteBuilder.suppressing()} while we
   * figure out what to do with <a href="http://goo.gl/qJBruX">{@code ConcurrentHashMap} support for
   * {@code entrySet().add()}</a>.
   */
  @J2ktIncompatible
  @GwtIncompatible // reflection