reply.class == payloadClass
    }

    def "handles nested objects which are not visible from root object ClassLoader"() {
        def parent = isolated(WrapperPayload, PayloadInterface)
        def wrapperClass = parent.loadClass(WrapperPayload.name)
        def payloadClass = isolated(parent, CustomPayload).loadClass(CustomPayload.name)
        assertNotVisible(wrapperClass, payloadClass)

    @Requires(value = IntegTestPreconditions.NotConfigCached, reason = "Isolated projects implies config cache")
    def "can use plugin #version with isolated projects"() {
        given:
        def versionNumber = VersionNumber.parse(version)

        when:
        usePluginVersion version

        then:
        scanRunner("-Dorg.gradle.unsafe.isolated-projects=true")

        then:
        configurationCache.assertStateLoaded()
    }

    @Issue("https://github.com/gradle/gradle/issues/26049")
    // Isolated Projects option is explicitly controlled by the test
    @Requires(IntegTestPreconditions.NotIsolatedProjects)
    def "isolated projects flag is part of the cache key"() {
        def isolatedProjects = new IsolatedProjectsFixture(this)

        when:
        configurationCacheRun "help"

        expect:
        rootProject.isolated.path == ":"
        rootProject.isolated.buildTreePath == ':'

        child1.isolated.path == ":child1"
        child1.isolated.buildTreePath == ":child1"

        child2.isolated.path == ":child1:child2"
        child2.isolated.buildTreePath == ":child1:child2"

        nestedRootProject.isolated.path == ":"

            // Counter is serialized and isolated prior to execution, so transforms will not see the increment in each tasks' doLast { } (which is good)
            file("build/libs1/test-1.3.jar.txt").readLines() == ["1", "2", "3", "4", "5"]
            file("build/libs1/test2-2.3.jar.txt").readLines() == ["1", "2", "3", "4", "5"]
        } else {

        """

        when: "fetching without Isolated Projects"
        def originalIdeaModel = fetchModel(IdeaProject)

        then:
        fixture.assertNoConfigurationCache()
        originalIdeaModel.modules.size() == 3
        originalIdeaModel.modules.every { it.children.isEmpty() } // IdeaModules are always flattened

        when: "fetching with Isolated Projects"
        executer.withArguments(ENABLE_CLI)

/**
 * Isolatable objects can return an isolated instance of the given type T from which this object was created.
 * An <b>isolated</b> instance has the same internal state as the original object on which this isolatable was based,
 * but it is guaranteed not to retain any references to mutable state from the original instance.
 * <p>

 */

package org.gradle.api;

import java.io.Serializable;

/**
 * Defines an action that is applied to objects of type {@link T}, with each target getting its own isolated action instance.
 *
 * Each isolated action is re-created through Configuration Cache serialization before it is applied to a target.
 * This approach ensures that sharing mutable state across targets via any means

     * @return a copy of this builder
     */
    IsolatedAntBuilder withClasspath(Iterable<File> classpath);

    /**
     * Executes the given closure against an isolated {@link org.gradle.api.AntBuilder} instance. The builder will
     * have visible to it an isolated version of Ant, Groovy and the specified libraries (if any). Each call to this
     * method is given a separate Ant project.
     */
    void execute(Closure antClosure);

 *
 * <ul>
 *     <li>Parallel execution of work items within a single task</li>
 *     <li>Execution in isolated contexts such as an isolated classloader or even a separate process</li>
 *     <li>Safe execution of multiple tasks in parallel</li>
 * </ul>
 *