** `Property` extends the `Provider` interface.
** The method link:{javadocPath}/org/gradle/api/provider/Property.html#set-T-[Property.set(T)] specifies a value for the property, overwriting whatever value may have been present.

     *
     * @see #properties(Map)
     * @see #property(String, Object)
     */
    public void setProperties(Map<String, Object> properties) {
        this.properties.clear();
        properties(properties);
    }

    /**
     * Adds a property to be written to the properties file.
     * <p>
     * A property's value will be coerced to a <code>String</code> with <code>String#valueOf(Object)</code> or a

    /**
     * Creates a shallow copy of this property. Further changes to this property (via {@code set(...)}, or {@code convention(Object...)}) do not
     * change the copy. However, the copy still reflects changes to the underlying providers that constitute this property. Consider the following snippet:
     * <pre>
     *     def upstream = objects.property(String).value("foo")
     *     def property = objects.property(String).value(upstream)

        property.get() == someValue()

        property.set(someOtherValue())
        property.present
        property.get() == someOtherValue()
    }

    def "can use null convention value"() {
        def property = propertyWithNoValue()
        assert property.getOrNull() != someValue()

        expect:
        nullConvention(property)

        !property.present
        property.getOrNull() == null

     */
    @Nonnull
    Map<String, String> getProperties(@Nonnull Project project);

    /**
     * Set a given project property.
     *
     * @param project the project to modify
     * @param key they property's key
     * @param value the value or {@code null} to unset the property
     */
    void setProperty(@Nonnull Project project, @Nonnull String key, @Nullable String value);

    @Nonnull

 *     of the Java collection this collection property corresponds to</li>
 *     <li>{@link CollectingSupplier}, when the collection is still being added to - in that case,
 *     the collecting supplier will wrap a {@link Collector} that lazily represents the yet-to-be realized contents of the collection - see below for details</li>
 * </ul>
 *
 * <h3>Collectors</h3>
 * <p>

        def property = property()
        property.set(someValue())
        property.set((String) null)

        expect:
        !property.present
        property.getOrNull() == null
        property.getOrElse(someValue()) == someValue()
        property.getOrElse(null) == null
    }

    def "can't set null provider to discard value"() {
        given:
        def property = property()

		<property name="queueIndex">"fess_crawler.queue"</property>
		<property name="queueShards">5</property>
		<property name="queueReplicas">1</property>
		<property name="dataIndex">"fess_crawler.data"</property>
		<property name="dataShards">5</property>
		<property name="dataReplicas">1</property>
		<property name="filterIndex">"fess_crawler.filter"</property>
		<property name="filterShards">5</property>

    }

    def "list property has empty list as value"() {
        expect:
        def property = factory.listProperty(String)
        property.present
        property.get().empty
    }

    def "can create list property with primitive type"() {
        given:
        def property = factory.listProperty(type)

        expect:
        property.elementType == boxedType

        where:

        then:
        !property.isFinalized()

        when:
        property.finalizeValue()

        then:
        property.isFinalized()
    }

    def "finalization checking works with providers"() {
        given:
        def property = propertyWithValue(someValue())

        expect:
        property.isPresent()
        !property.isFinalized()

        when: