/**
 * Signifies that a public API (public class, method or field) is subject to incompatible changes,
 * or even removal, in a future release. An API bearing this annotation is exempt from any
 * compatibility guarantees made by its containing library. Note that the presence of this
 * annotation implies nothing about the quality or performance of the API in question, only the fact
 * that it is not "API-frozen."
 *

 * <i>other type</i> of supplier is expected, use the method reference {@code supplier::get}. A
 * future version of {@code com.google.common.base.Supplier} will be made to <i>extend</i> {@code
 * java.util.function.Supplier}, making conversion code necessary only in one direction. At that
 * time, this interface will be officially discouraged.
 *
 * @author Harry Heymann
 * @since 2.0
 */

 *   new MySubtypeTests().testAllDeclarations();
 * }
 * }</pre>
 *
 * The calls to {@link #isSubtype} and {@link #notSubtype} tells the framework what assertions need
 * to be made.
 *
 * <p>The declaration methods must be public.
 */
@AndroidIncompatible // only used by android incompatible tests.
abstract class SubtypeTester implements Cloneable {

   * the {@code shutdownNow} method. First, "best-effort" with regards to canceling running tasks is
   * implemented as "no-effort". No interrupts or other attempts are made to stop threads executing
   * tasks. Second, the returned list will always be empty, as any submitted task is considered to
   * have started execution. This applies also to tasks given to {@code invokeAll} or {@code

   *   <li><b>If the character at the specified index is not a surrogate, it is returned.</b>
   *   <li>If the first character was a high surrogate value, then an attempt is made to read the
   *       next character.
   *       <ol>
   *         <li><b>If the end of the sequence was reached, the negated value of the trailing high
   *             surrogate is returned.</b>

   * currently {@code expectedOldCount}. If {@code element} does not appear in the multiset exactly
   * {@code expectedOldCount} times, no changes will be made.
   *
   * @return {@code true} if the change was successful. This usually indicates that the multiset has
   *     been modified, but not always: in the case that {@code expectedOldCount == newCount}, the

                <!-- TODO(cpovirk): Use .mvn/jvm.config instead (per
                     https://errorprone.info/docs/installation#maven) if it can
                     be made not to interfere with JDK8 or if we stop building
                     with JDK8. -->
                <arg>-J--add-exports=jdk.compiler/com.sun.tools.javac.api=ALL-UNNAMED</arg>

 *
 * <p>If the precondition is not met, the {@code Preconditions} method throws an unchecked exception
 * of a specified type, which helps the method in which the exception was thrown communicate that
 * its caller has made a mistake. This allows constructs such as
 *
 * <pre>{@code
 * public static double sqrt(double value) {
 *   if (value < 0) {
 *     throw new IllegalArgumentException("input is negative: " + value);
 *   }

  /**
   * Returns an unmodifiable iterable over the nodes in a tree structure, using pre-order traversal.
   * That is, each node's subtrees are traversed after the node itself is returned.
   *
   * <p>No guarantees are made about the behavior of the traversal when nodes change while iteration
   * is in progress or when the iterators generated by {@link #children} are advanced.
   *

into the air off all its feet at once, with a yelp of delight,
and rushed at the stick, and made believe to worry it; then Alice
dodged behind a great thistle, to keep herself from being run
over; and the moment she appeared on the other side, the puppy
made another rush at the stick, and tumbled head over heels in
its hurry to get hold of it; then Alice, thinking it was very