** `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.

    /**
     * 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)

 *     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()

The property must not have any setter methods.

Here is an example of a task type with an `uri` property of type `URI`:

[source,java]
.Download.java
----
include::{snippetsPath}/plugins/mutableManagedProperty/groovy/buildSrc/src/main/java/Download.java[tags=download]
----

Note that for a property to be considered a mutable managed property, the property's getter methods must be `abstract` and have `public` or `protected` visibility.

                * property(a, literal(33)) -> ShadowedProperty(underlayProperty=property(a, literal(3)), overlayProperty=property(a, literal(33)))
                    - literal(33) -> FromOverlay(documentNode=property(a, literal(33)))
                * property(b, literal(6)) -> FromOverlay(documentNode=property(b, literal(6)))
                    - literal(6) -> FromOverlay(documentNode=property(b, literal(6)))

            tasks.create("thing", MyTask) {
                println("property = \$count")
                count = 12
            }
        """

        when:
        succeeds("thing")

        then:
        outputContains("property = task ':thing' property 'count'")
        outputContains("count = 12")
    }

    def "reports failure to query managed Property<T> with no value"() {
        given:
        buildFile << """

        when:
        configurationCacheRun("-Dsome.property.1=1", "-Dsome.property.2=2", "print")

        then:
        configurationCache.assertStateStored()
        outputContains("Configuration: some.property.1 = 0")
        outputContains("Configuration: some.property.2 = 2")

        when:
        configurationCacheRun("-Dsome.property.1=-1", "-Dsome.property.2=2", "print")

        then:

        "${Property.name}<String>"            | "objects.property(String); v.set('abc')"              | "objects.property(String); v.set('123')"                     | "Type 'SomeTask': property 'v' of mutable type 'org.gradle.api.provider.Property' is writable. Properties of type 'org.gradle.api.provider.Property' are already mutable. Possible solution: Remove the 'setV' method. ${learnAt("validation_problems",...

The value of this property is derived from:
  - extension 'custom2' property 'source'
  - extension 'custom1' property 'source'""")
    }

    def "can use property with no value as optional ad hoc task input property"() {
        given:
        buildFile << """

def prop = project.objects.property(String)

task thing {