* conformance of concrete {@link Map} subclasses to that contract.
 *
 * @param <K> the type of keys used by the maps under test
 * @param <V> the type of mapped values used the maps under test
 * @author George van den Driessche
 */
// TODO: Descriptive assertion messages, with hints as to probable fixes.

        : Iterators.retainAll(removeFrom.iterator(), elementsToRetain);
  }

  /**
   * Removes, from an iterable, every element that satisfies the provided predicate.
   *
   * <p>Removals may or may not happen immediately as each element is tested against the predicate.
   * The behavior of this method is not specified if {@code predicate} is dependent on {@code
   * removeFrom}.
   *

   * inputs, with counts equal to the result of applying {@code countFunction} to the inputs.
   * Elements are added in encounter order.
   *
   * <p>If the mapped elements contain duplicates (according to {@link Object#equals}), the element
   * will be added more than once, with the count summed over all appearances of the element.
   *

    // Slice it starting at offset 10.
    ByteSource slice = source.slice(10, 5);

    // Open a stream to the slice.
    InputStream in = slice.openStream();

    // Append 10 more bytes to the source.
    source.append(newPreFilledByteArray(5, 10));

    // The stream reports no bytes... importantly, it doesn't read the byte at index 5 when it
    // should be reading the byte at index 10.

    public String toString() {
      StringBuilder builder = new StringBuilder("BaseEncoding.");
      builder.append(alphabet);
      if (8 % alphabet.bitsPerChar != 0) {
        if (paddingChar == null) {
          builder.append(".omitPadding()");
        } else {
          builder.append(".withPadChar('").append(paddingChar).append("')");
        }
      }
      return builder.toString();
    }

    @Override

 *       (such as by passing an invalid argument), use the utilities of the {@link Preconditions}
 *       class instead.
 *   <li>If checking an <i>impossible</i> condition (which <i>cannot</i> happen unless your own
 *       class or its <i>trusted</i> dependencies is badly broken), this is what ordinary Java
 *       assertions are for. Note that assertions are not enabled by default; they are essentially

 *   <li>enqueuing weak references to unreachable referents in their reference queue
 * </ul>
 *
 * <p>This class uses (possibly repeated) invocations of {@link java.lang.System#gc()} to cause
 * finalization to happen. However, a call to {@code System.gc()} is specified to be no more than a
 * hint, so this technique may fail at the whim of the JDK implementation, for example if a user

      @Override
      public Appendable append(CharSequence csq) throws IOException {
        a.append(csq);
        return this;
      }

      @Override
      public Appendable append(CharSequence csq, int start, int end) throws IOException {
        a.append(csq, start, end);
        return this;
      }

      @Override
      public Appendable append(char c) throws IOException {
        a.append(c);

      @Override
      public Appendable append(CharSequence csq) throws IOException {
        a.append(csq);
        return this;
      }

      @Override
      public Appendable append(CharSequence csq, int start, int end) throws IOException {
        a.append(csq, start, end);
        return this;
      }

      @Override
      public Appendable append(char c) throws IOException {
        a.append(c);

        break;
      }
      builder.append(template, templateStart, placeholderStart);
      builder.append(args[i++]);
      templateStart = placeholderStart + 2;
    }
    builder.append(template, templateStart, template.length());

    // if we run out of placeholders, append the extra args in square braces
    if (i < args.length) {
      builder.append(" [");
      builder.append(args[i++]);
      while (i < args.length) {