* checked.
   *
   * <p>If a {@code Guard} is passed into any method of a {@code Monitor} other than the one it is
   * associated with, an {@link IllegalMonitorStateException} is thrown.
   *
   * @since 10.0
   */
  public abstract static class Guard {

    @Weak final Monitor monitor;
    final Condition condition;

    @GuardedBy("monitor.lock")

    Monitor monitor = new Monitor();
    assertThrows(IllegalMonitorStateException.class, monitor::leave);
  }

  public void testGetWaitQueueLengthWithWrongMonitorThrowsIMSE() {
    Monitor monitor1 = new Monitor();
    Monitor monitor2 = new Monitor();
    FlagGuard guard = new FlagGuard(monitor2);
    assertThrows(IllegalMonitorStateException.class, () -> monitor1.getWaitQueueLength(guard));
  }

    Monitor monitor = new Monitor();
    assertThrows(IllegalMonitorStateException.class, monitor::leave);
  }

  public void testGetWaitQueueLengthWithWrongMonitorThrowsIMSE() {
    Monitor monitor1 = new Monitor();
    Monitor monitor2 = new Monitor();
    FlagGuard guard = new FlagGuard(monitor2);
    assertThrows(IllegalMonitorStateException.class, () -> monitor1.getWaitQueueLength(guard));
  }

  }

  public final void testWaitFor_withoutEnter() throws Exception {
    TestGuard guard = new TestGuard(true);
    thread1.callAndAssertThrows(IllegalMonitorStateException.class, waitFor(), guard);
  }

  public void testNulls() {
    monitor.enter(); // Inhibit IllegalMonitorStateException
    new NullPointerTester()
        .setDefault(Monitor.Guard.class, new TestGuard(true))
        .testAllPublicInstanceMethods(monitor);
  }

          monitor1.enter();
        }
        try {
          method.invoke(monitor1, arguments.toArray());
          fail("expected IllegalMonitorStateException");
        } catch (InvocationTargetException e) {
          assertThat(e.getTargetException()).isInstanceOf(IllegalMonitorStateException.class);
        } finally {
          if (occupyMonitor) {
            monitor1.leave();
          }
        }
      }
    };

          monitor1.enter();
        }
        try {
          method.invoke(monitor1, arguments.toArray());
          fail("expected IllegalMonitorStateException");
        } catch (InvocationTargetException e) {
          assertThat(e.getTargetException()).isInstanceOf(IllegalMonitorStateException.class);
        } finally {
          if (occupyMonitor) {
            monitor1.leave();
          }
        }
      }
    };

  }

  public final void testWaitFor_withoutEnter() throws Exception {
    TestGuard guard = new TestGuard(true);
    thread1.callAndAssertThrows(IllegalMonitorStateException.class, waitFor(), guard);
  }

  public void testNulls() {
    monitor.enter(); // Inhibit IllegalMonitorStateException
    new NullPointerTester()
        .setDefault(Monitor.Guard.class, new TestGuard(true))
        .testAllPublicInstanceMethods(monitor);
  }