} catch (Exception e) {
            fail("writeThreadDump should handle invalid paths gracefully: " + e.getMessage());
        }
    }

    @Test
    public void test_writeThreadDump_withNullPath() {
        try {
            ThreadDumpUtil.writeThreadDump(null);
            // Should not throw exception but log warning
        } catch (Exception e) {

    // The opposite order should fail (Policies.THROW).
    PotentialDeadlockException firstException = null;
    lockB.lock();
    PotentialDeadlockException expected =
        assertThrows(PotentialDeadlockException.class, () -> lockA.lock());
    checkMessage(expected, "LockB -> LockA", "LockA -> LockB");
    firstException = expected;
    // Second time should also fail, with a cached causal chain.

    // The opposite order should fail (Policies.THROW).
    PotentialDeadlockException firstException = null;
    lockB.lock();
    PotentialDeadlockException expected =
        assertThrows(PotentialDeadlockException.class, () -> lockA.lock());
    checkMessage(expected, "LockB -> LockA", "LockA -> LockB");
    firstException = expected;
    // Second time should also fail, with a cached causal chain.

                  try {
                    peeker.getDone(input2Failed);
                    fail("Peeker.getDone() should fail for failed inputs");
                  } catch (ExecutionException expected) {
                  }
                  try {
                    peeker.getDone(nonInput);
                    fail("Peeker should not be able to peek into non-input ClosingFuture.");

    @Override
    public void oneArg(String s) {
      // Fail: missing NPE for s
    }
  }

  public void testFailOneArgDoesntThrowNpe() {
    shouldFail(new FailOneArgDoesntThrowNpe());
  }

  private static class FailOneArgThrowsWrongType extends PassObject {
    @Override
    public void oneArg(String s) {
      doThrow(s); // Fail: throwing non-NPE exception for null s
    }
  }

                  + ".");
      return;
    }
    fail();
  }

  public void testEqualsOnReturnValues_bad() throws Exception {
    try {
      tester.forAllPublicStaticMethods(BadEqualsFactory.class).testEquals();
    } catch (AssertionError expected) {
      return;
    }
    fail();
  }

  private static class BadEqualsFactory {

    // Test add method with null name
    @Test
    public void test_add_nullName() {
        TestScriptEngine engine = new TestScriptEngine();
        try {
            scriptEngineFactory.add(null, engine);
            fail("Should throw IllegalArgumentException for null name");
        } catch (IllegalArgumentException e) {
            assertTrue(e.getMessage().contains("Both name and scriptEngine parameters are required"));

                  try {
                    peeker.getDone(input2Failed);
                    fail("Peeker.getDone() should fail for failed inputs");
                  } catch (ExecutionException expected) {
                  }
                  try {
                    peeker.getDone(nonInput);
                    fail("Peeker should not be able to peek into non-input ClosingFuture.");

                throw new IOException("Test exception");
            }
        };

        try {
            SearchEngineUtil.getXContentString(xContent, XContentType.JSON);
            fail("Should throw IORuntimeException");
        } catch (IORuntimeException e) {
            assertTrue(e.getCause() instanceof IOException);
            assertEquals("Test exception", e.getCause().getMessage());
        }

        } catch (Exception e) {
            fail("Unexpected exception: " + e.getMessage());
        }
    }

    @Test
    public void test_install_blankUrl() {
        PluginHelper testHelper = new PluginHelper();
        Artifact artifact = new Artifact("test", "1.0.0", "");

        try {
            testHelper.install(artifact);
            fail("Expected PluginException");