import java.util.Set;
import java.util.concurrent.atomic.AtomicInteger;
import javax.annotation.CheckForNull;

/**
 * An object of this class encapsulates type mappings from type variables. Mappings are established
 * with {@link #where} and types are resolved using {@link #resolveType}.
 *
 * <p>Note that usually type mappings are already implied by the static type hierarchy (for example,

import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * To be implemented by test generators of things that can contain elements. Such things include
 * both {@link Collection} and {@link Map}; since there isn't an established collective noun that
 * encompasses both of these, 'container' is used.
 *
 * @author George van den Driessche
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault

import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * To be implemented by test generators of things that can contain elements. Such things include
 * both {@link Collection} and {@link Map}; since there isn't an established collective noun that
 * encompasses both of these, 'container' is used.
 *
 * @author George van den Driessche
 */
@GwtCompatible
@ElementTypesAreNonnullByDefault

    lockB.unlock();
    lockA.lock();
  }

  // Tests transitive deadlock detection.
  public void testDeadlock_threeLocks() {
    // Establish an ordering from lockA -> lockB.
    lockA.lock();
    lockB.lock();
    lockB.unlock();
    lockA.unlock();

    // Establish an ordering from lockB -> lockC.
    lockB.lock();
    lockC.lock();
    lockB.unlock();

    // lockC -> lockA should fail.

    lockB.unlock();
    lockA.lock();
  }

  // Tests transitive deadlock detection.
  public void testDeadlock_threeLocks() {
    // Establish an ordering from lockA -> lockB.
    lockA.lock();
    lockB.lock();
    lockB.unlock();
    lockA.unlock();

    // Establish an ordering from lockB -> lockC.
    lockB.lock();
    lockC.lock();
    lockB.unlock();

    // lockC -> lockA should fail.