System.clearProperty("123");
        System.clearProperty("test_var");
    }

    @Test
    public void test_resolve_edgeCases() {
        // Test empty property replacement
        System.setProperty("empty", "");
        String value = "${empty}";
        assertEquals("", ResourceUtil.resolve(value));

        // Test property with just spaces
        System.setProperty("spaces", "   ");

    expectContents();
  }

  // retainAll(null)

  /*
   * AbstractCollection fails the retainAll(null) test when the subject
   * collection is empty, but we'd still like to test retainAll(null) when we
   * can. We split the test into empty and non-empty cases. This allows us to
   * suppress only the former.
   */

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ZERO)

                  @Override
                  protected Set<String> create(String[] elements) {
                    return union(emptySet(), emptySet());
                  }
                })
            .named("empty U empty")
            .withFeatures(CollectionSize.ZERO, CollectionFeature.ALLOWS_NULL_VALUES)
            .createTestSuite());

    suite.addTest(
        SetTestSuiteBuilder.using(

    }

    /**
     * Returns the bundle. Returns <code>null</code> if not found.
     *
     * @param name the resource bundle name (must not be {@literal null} or empty)
     * @param locale the locale
     * @param classLoader the class loader (must not be {@literal null} or empty)
     * @return {@link ResourceBundle}
     * @see ResourceBundle#getBundle(String, Locale, ClassLoader)
     */

        // Mock successful but empty response
        when(treeHandle.send(any(), any(), (RequestParam[]) any())).thenAnswer(invocation -> {
            // The response is the second argument
            Object response = invocation.getArgument(1);
            // Return it unchanged (which will have default values = empty results)
            return response;
        });

     *            The fully qualified name of the desired class. Must not be {@literal null} or empty.
     * @param loader
     *            The class loader to use to load the class
     * @return The {@link Class} object for the class with the specified name
     * @throws EmptyArgumentException
     *             If the class name is {@literal null} or empty
     * @throws ClassNotFoundRuntimeException
     *             If the class cannot be found

            pacString.check(testString);
        }, "A PACDecodingException should be thrown for a non-empty string with a zero pointer.");

        // Verify the exception message
        assertEquals("Non-empty string", exception.getMessage(), "The exception message is not correct.");
    }

    /**

  public void testConcat() {
    assertThat(Chars.concat()).isEqualTo(EMPTY);
    assertThat(Chars.concat(EMPTY)).isEqualTo(EMPTY);
    assertThat(Chars.concat(EMPTY, EMPTY, EMPTY)).isEqualTo(EMPTY);
    assertThat(Chars.concat(ARRAY1)).isEqualTo(ARRAY1);
    assertThat(Chars.concat(ARRAY1)).isNotSameInstanceAs(ARRAY1);
    assertThat(Chars.concat(EMPTY, ARRAY1, EMPTY)).isEqualTo(ARRAY1);
    assertThat(Chars.concat(ARRAY1, ARRAY1, ARRAY1))

        @Test
        @DisplayName("should create empty result")
        void shouldCreateEmptyResult() {
            UpgradeResult result = UpgradeResult.empty();

            assertTrue(result.success(), "Empty result should be successful");
            assertEquals(0, result.processedCount(), "Empty result should have no processed POMs");
            assertEquals(0, result.modifiedCount(), "Empty result should have no modified POMs");

        EntraIdAuthenticator authenticator = new EntraIdAuthenticator();
        authenticator.setMaxGroupDepth(2);

        // Test that depth limit returns empty arrays when depth is exceeded
        // With depth limit set to 2, depth 10 should return empty arrays
        Pair<String[], String[]> result = authenticator.getParentGroup(null, "test-id", 10);
        assertNotNull(result);
        assertEquals(0, result.getFirst().length);