repos.add(artifactRepositoryFactory.createArtifactRepository(
                "repo1", "string://url1", new ArtifactRepositoryLayoutStub(), null, null));
        repos.add(artifactRepositoryFactory.createArtifactRepository(
                "repo2", "string://url2", new ArtifactRepositoryLayoutStub(), null, null));

        StringWagon wagon = (StringWagon) wagonManager.getWagon("string");

    }

    /**
     * Asserts that the argument is not <code>null</code>.
     *
     * @param argName
     *            The name of the argument that must not be {@code null}.
     * @param argValue
     *            The value of the argument.
     * @throws NullArgumentException
     *             If the argument is <code>null</code>.
     */

        if (value != null) {
            final StringBuilder buf = new StringBuilder();
            buf.append("-D").append(name).append("=").append(value);
            if (appendValue != null) {
                buf.append(appendValue);
            }
            cmdList.add(buf.toString());
        } else if (defaultValue != null) {
            cmdList.add("-D" + name + "=" + defaultValue);

        // Match by share name or server address, safely handling nulls
        boolean shareMatch = resourceName != null && shareName != null && resourceName.equalsIgnoreCase(shareName);

        String serverAddress = registration.getServerAddress() != null ? registration.getServerAddress().getHostAddress() : null;
        boolean addressMatch = java.util.Objects.equals(resourceName, serverAddress);

        RoleCQ cq = new RoleCQ();
        if (queryLambda != null) {
            queryLambda.callback(cq);
        }
        FilterAggregationBuilder builder = regFilterA(name, cq.getQuery());
        if (opLambda != null) {
            opLambda.callback(builder);
        }
        if (aggsLambda != null) {
            RoleCA ca = new RoleCA();
            aggsLambda.callback(ca);

        assertNull(exception.getCause());
        assertNull(exception.getMessage());
        assertTrue(exception instanceof FessSystemException);
    }

    public void test_constructorWithNullMessageAndCause() {
        // Test constructor with null message and null cause
        SearchQueryException exception = new SearchQueryException(null, null);

        assertNull(exception.getMessage());

     *
     * @param groupId the group identifier, or {@code null} is unspecified
     * @param artifactId the artifact identifier, or {@code null} is unspecified
     * @param version the artifact version, or {@code null} is unspecified
     * @param classifier the artifact classifier, or {@code null} is unspecified
     * @param extension the artifact extension, or {@code null} is unspecified

        fileTypeHelper.add(null, "test");
        assertEquals("test", fileTypeHelper.get(null));
    }

    public void test_add_withEmptyMimetype() {
        fileTypeHelper.add("", "empty");
        assertEquals("empty", fileTypeHelper.get(""));
    }

    public void test_add_withNullFiletype() {
        fileTypeHelper.add("test/null", null);

  public void testPutIfAbsent_nullKeyUnsupported() {
    assertThrows(NullPointerException.class, () -> getMap().putIfAbsent(null, v3()));
    expectUnchanged();
    expectNullKeyMissingWhenNullKeysUnsupported(
        "Should not contain null key after unsupported putIfAbsent(null, value)");
  }

  @MapFeature.Require(value = SUPPORTS_PUT, absent = ALLOWS_NULL_VALUES)

        assertDoesNotThrow(() -> resp.writeParametersWireFormat(null, 0));
        assertDoesNotThrow(() -> resp.writeDataWireFormat(null, 0));
        assertDoesNotThrow(() -> resp.readSetupWireFormat(null, 0, 0));
        assertDoesNotThrow(() -> resp.readParametersWireFormat(null, 0, 0));
        assertDoesNotThrow(() -> resp.readDataWireFormat(null, 0, 0));