}

    @Test
    void testPropertiesClear() {
        // Test for issue #11552: NullPointerException when clearing properties
        Model model = new Model();
        model.addProperty("key1", "value1");
        model.addProperty("key2", "value2");
        assertEquals(2, model.getProperties().size());

        // This should not throw NullPointerException
        model.getProperties().clear();

              <exclude>org.apache.maven.model.Contributor#addProperty(java.lang.String,java.lang.String):METHOD_REMOVED</exclude>
              <exclude>org.apache.maven.model.Dependency#clearManagementKey():METHOD_REMOVED</exclude>
              <exclude>org.apache.maven.model.ModelBase#addProperty(java.lang.String,java.lang.String):METHOD_REMOVED</exclude>

  val packageName = "okhttp3.internal.idn"
  val idnaMappingTable = ClassName(packageName, "IdnaMappingTable")

  return FileSpec
    .builder(packageName, "IdnaMappingTableInstance")
    .addProperty(
      PropertySpec
        .builder("IDNA_MAPPING_TABLE", idnaMappingTable)
        .addModifiers(KModifier.INTERNAL)
        .initializer(
          """
          |%T(⇥
          |sections = "%L",

                    property.setName(field.getKey());
                    property.setValue(dispatcherConfigResult.get(field.getKey()).getResult());
                    dispatcherConfig.addProperty(property);
                }
                if (!dispatcherConfig.getProperties().isEmpty()) {
                    config.addConfiguration(dispatcherConfig);
                }
            }
        }

    }

    /**
     * Adds a property to the extractor.
     *
     * @param key   the key of the property
     * @param value the value of the property
     */
    public void addProperty(final String key, final String value) {
        if (StringUtil.isBlank(key) || StringUtil.isBlank(value)) {
            throw new CrawlerSystemException("key or value is null.");
        }

     * Adds a parser property configuration.
     *
     * @param key the property key
     * @param value the property value
     * @throws CrawlerSystemException if key or value is null
     */
    public void addProperty(final String key, final String value) {
        if (StringUtil.isBlank(key) || StringUtil.isBlank(value)) {