import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.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("test runners must not instantiate and run this directly, only via suites we build")

import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.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("test runners must not instantiate and run this directly, only via suites we build")

import java.util.Collection;
import java.util.List;
import org.jspecify.annotations.NullMarked;

/**
 * Creates collections containing unhashable sample elements, to be tested.
 *
 * @author Regina O'Dell
 */
@GwtCompatible
@NullMarked
public abstract class TestUnhashableCollectionGenerator<T extends Collection<UnhashableObject>>
    implements TestCollectionGenerator<UnhashableObject> {

 *       have, of returning a new, independent iterator
 * </ul>
 *
 * <p>Because of this situation, any public method accepting an iterable should invoke the {@code
 * iterator} method only once, and should be tested using this class. Exceptions to this rule should
 * be clearly documented.
 *
 * <p>Note that although your APIs should be liberal in what they accept, your methods which

    /*
     * We'll give ourselves a pass on testing all the possible ways of breaking the constraint,
     * because we know that newClassMap() is implemented using ConstrainedMap which is itself
     * well-tested. A purist would object to this, but what can I say, we're dirty cheaters.
     */
    map.put(Integer.class, new Integer(5));
    assertThrows(ClassCastException.class, () -> map.put(Double.class, new Long(42)));

 *       have, of returning a new, independent iterator
 * </ul>
 *
 * <p>Because of this situation, any public method accepting an iterable should invoke the {@code
 * iterator} method only once, and should be tested using this class. Exceptions to this rule should
 * be clearly documented.
 *
 * <p>Note that although your APIs should be liberal in what they accept, your methods which

      for (int i = 0; i < expected.length; i++) {
        assertEquals(expected[i], got[i]);
      }
    }
  }

  // Assumes that AbstractNonStreamingHashFunction works properly (must be tested elsewhere!)
  private static class Control extends AbstractNonStreamingHashFunction {
    @Override
    public HashCode hashBytes(byte[] input, int off, int len) {

  @Param ExceptionType exceptionType;

  /**
   * The number of other exception types in the cache of known-good exceptions and the number of
   * other {@code ClassValue} entries for the exception type to be tested. This lets us evaluate
   * whether our solution scales to use with multiple exception types and to whether it is affected
   * by other {@code ClassValue} users. Some of the benchmarked implementations don't use one or

        return map.isEmpty();
    }

    /**
     * Returns true if this set contains the specified element.
     *
     * @param o
     *            element whose presence in this set is to be tested.
     * @return true if this set contains the specified element.
     */
    @Override
    public boolean contains(final Object o) {
        return map.containsKey(o);
    }

    /**

    // Then, run the actual tests under each alternative classloader:

    /*
     * Under Java 8, there is no need to test the no-VarHandle case here: It's already tested by the
     * main AbstractFutureTest, which uses the default AtomicHelper, which we verified above to be
     * UnsafeAtomicHelper.
     */
    if (!isJava8()) {
      runTestMethod(NO_VAR_HANDLE);
    }