import java.util.Collection;
import org.checkerframework.checker.nullness.qual.Nullable;
import org.junit.Ignore;

/**
 * Base class for collection testers.
 *
 * @param <E> the element type of the collection to be tested.
 * @author Kevin Bourrillion
 */
@GwtCompatible
@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@ElementTypesAreNonnullByDefault

import java.io.Reader;
import java.io.StringReader;
import java.io.StringWriter;
import java.io.Writer;
import java.lang.reflect.AnnotatedElement;
import java.lang.reflect.GenericDeclaration;
import java.lang.reflect.Type;
import java.math.BigDecimal;
import java.math.BigInteger;
import java.nio.Buffer;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.DoubleBuffer;
import java.nio.FloatBuffer;

   * @param type the type of the elements
   * @return a newly-allocated array into which all the elements of the iterable have been copied
   */
  @GwtIncompatible // Array.newInstance(Class, int)
  public static <T extends @Nullable Object> T[] toArray(
      Iterable<? extends T> iterable, Class<@NonNull T> type) {
    return toArray(iterable, ObjectArrays.newArray(type, 0));
  }

 * except that the method parameter must accept whatever condition-like object is passed into {@code
 * callAndAssertWaits} by the test.
 *
 * @param <L> the type of the lock-like object to be used
 * @author Justin T. Sampson
 */
public final class TestThread<L> extends Thread implements TearDown {

  private static final long DUE_DILIGENCE_MILLIS = 100;

 * by multiple concurrent threads.
 *
 * <p>When evaluated as a {@link Function}, a cache yields the same result as invoking {@link
 * #getUnchecked}.
 *
 * @param <K> the type of the cache's keys, which are not permitted to be null
 * @param <V> the type of the cache's values, which are not permitted to be null
 * @author Charles Fry
 * @since 11.0
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault

 *
 * <p>Implementations of this interface are expected to be thread-safe, and can be safely accessed
 * by multiple concurrent threads.
 *
 * @param <K> the type of the cache's keys, which are not permitted to be null
 * @param <V> the type of the cache's values, which are not permitted to be null
 * @author Charles Fry
 * @since 10.0
 */
@DoNotMock("Use CacheBuilder.newBuilder().build()")
@GwtCompatible

   *
   * (PatternFilenameFilter is of course one of those classes that shouldn't be a publicly visible
   * class to begin with but rather something returned from a static factory method whose declared
   * return type is plain FilenameFilter. If we made such a change, then the annotation we choose
   * here would have no significance to end users, who would be forced to conform to the signature
   * used in FilenameFilter.)
   */
  @Override

  private static final class AvlNode<E extends @Nullable Object> {
    /*
     * For "normal" nodes, the type of this field is `E`, not `@Nullable E` (though note that E is a
     * type that can include null, as in a TreeMultiset<@Nullable String>).
     *
     * For the header node, though, this field contains `null`, regardless of the type of the
     * multiset.
     *

    return policy == Policies.DISABLED
        ? new ReentrantReadWriteLock(fair)
        : new CycleDetectingReentrantReadWriteLock(new LockGraphNode(lockName), fair);
  }

  // A static mapping from an Enum type to its set of LockGraphNodes.
  private static final ConcurrentMap<
          Class<? extends Enum<?>>, Map<? extends Enum<?>, LockGraphNode>>
      lockGraphNodesPerType = new MapMaker().weakKeys().makeMap();

  }

  @Override
  public Iterator<E> iterator() {
    if (iterator == null) {
      // TODO: throw something else? Do we worry that people's code and tests
      // might be relying on this particular type of exception?
      throw new IllegalStateException();
    }
    try {
      return iterator;
    } finally {
      iterator = null;
    }
  }