* <pre>
     * a:1.0
     * a:2.0
     * </pre>
     */
    @Test
    void testEqual() {
        ResolutionNode a1n = createResolutionNode(a1);
        ResolutionNode a2n = createResolutionNode(a2);

        assertResolveConflict(a1n, a1n, a2n);
    }

    /**
     * Tests that <code>a:2.0</code> wins in the scenario:
     * <pre>
     * a:2.0
     * a:1.0
     * </pre>

 * final WeakHashMap<Object, Object> map = new WeakHashMap<>();
 * map.put(new Object(), Boolean.TRUE);
 * GcFinalization.awaitDone(new FinalizationPredicate() {
 *   public boolean isDone() {
 *     return map.isEmpty();
 *   }
 * });
 * }</pre>
 *
 * <p>Even if your non-test code does not use finalization, you can use this class to test for
 * leaks, by ensuring that objects are no longer strongly referenced:
 *
 * <pre>{@code

    InputStream in = new ByteArrayInputStream(PRE_FILLED_100);
    byte[] b = ByteStreams.toByteArray(in, 100);
    assertThat(b).isEqualTo(PRE_FILLED_100);
  }

  public void testToByteArray_withSize_givenSmallerSize() throws IOException {
    InputStream in = new ByteArrayInputStream(PRE_FILLED_100);
    byte[] b = ByteStreams.toByteArray(in, 80);
    assertThat(b).isEqualTo(PRE_FILLED_100);
  }

   *
   * <pre>
   * for (Foo foo : foos) {
   *   try {
   *     foo.bar();
   *   } catch (BarException | RuntimeException | Error t) {
   *     failure = t;
   *   }
   * }
   * if (failure != null) {
   *   throwIfInstanceOf(failure, BarException.class);
   *   throwIfUnchecked(failure);
   *   throw new AssertionError(failure);
   * }
   * </pre>
   *
   * @since 20.0
   */

   *
   * <pre>
   * for (Foo foo : foos) {
   *   try {
   *     foo.bar();
   *   } catch (BarException | RuntimeException | Error t) {
   *     failure = t;
   *   }
   * }
   * if (failure != null) {
   *   throwIfInstanceOf(failure, BarException.class);
   *   throwIfUnchecked(failure);
   *   throw new AssertionError(failure);
   * }
   * </pre>
   *
   * @since 20.0
   */

 * then Lock B, while another thread acquires Lock B, and then Lock A:
 *
 * <pre>
 * Thread1: acquire(LockA) --X acquire(LockB)
 * Thread2: acquire(LockB) --X acquire(LockA)
 * </pre>
 *
 * <p>Neither thread will progress because each is waiting for the other. In more complex
 * applications, cycles can arise from interactions among more than 2 locks:
 *
 * <pre>
 * Thread1: acquire(LockA) --X acquire(LockB)

     * <p>
     * 次のように使います．
     * </p>
     *
     * <pre>
     * ObjectUtil.defaultValue(null, "NULL")  = "NULL"
     * ObjectUtil.defaultValue(null, 1)    = 1
     * ObjectUtil.defaultValue(Boolean.TRUE, true) = Boolean.TRUE
     * ObjectUtil.defaultValue(null, null) = null
     * </pre>
     *
     * @param <T>
     *            オブジェクトの型
     * @param t

 * implement it:
 *
 * <pre>{@code
 * // won't work
 * TreeTraverser<NodeType> traverser = node -> node.getChildNodes();
 * }</pre>
 *
 * Instead, you can pass a lambda expression to the {@code using} factory method:
 *
 * <pre>{@code
 * TreeTraverser<NodeType> traverser = TreeTraverser.using(node -> node.getChildNodes());
 * }</pre>
 *
 * @author Louis Wasserman
 * @since 15.0

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

/**
 * Tester for equals() and hashCode() methods of a class.
 *
 * <p>The simplest use case is:
 *
 * <pre>
 * new EqualsTester().addEqualityGroup(foo).testEquals();
 * </pre>
 *
 * <p>This tests {@code foo.equals(foo)}, {@code foo.equals(null)}, and a few other operations.
 *

   * {@code Optional} class. However, this common usage:
   *
   * <pre>{@code
   * for (Foo foo : possibleFoo.asSet()) {
   *   doSomethingWith(foo);
   * }
   * }</pre>
   *
   * ... can be replaced with:
   *
   * <pre>{@code
   * possibleFoo.ifPresent(foo -> doSomethingWith(foo));
   * }</pre>
   *