given:
        withParallelThreads(2)
        buildFile << """
            def dir = rootProject.file("dir")

            aPing.destroyables.register dir

            bPing.outputs.file dir
        """

        expect:
        2.times {
            blockingServer.expectConcurrent(1, ":aPing", ":bPing")
            run ":aPing", ":bPing"

    }

    private
    suspend fun WriteContext.writeDestroyablesOf(task: TaskInternal) {
        val destroyables = (task.destroyables as TaskDestroyablesInternal).registeredFiles
        if (destroyables.isEmpty) {
            writeBoolean(false)
        } else {
            writeBoolean(true)
            write(destroyables)
        }
    }

    private
    suspend fun ReadContext.readDestroyablesOf(task: TaskInternal) {

import org.gradle.internal.fingerprint.FileNormalizer;
import org.gradle.internal.fingerprint.LineEndingSensitivity;

import javax.annotation.Nullable;

/**
 * Visits properties of beans which are inputs, outputs, destroyables, local state, service references or software types.
 */
public interface PropertyVisitor {

        taskProperties.outputFileProperties.empty
        taskProperties.destroyableFiles.empty
    }

    def "registers destroyables"() {
        def destroyable = new File(temporaryFolder.file('destroyable').createFile().absolutePath)
        given:
        def task = expectTaskCreated(TaskWithDestroyable, destroyable)

        when:
        def taskProperties = DefaultTaskProperties.resolve(propertyWalker, fileCollectionFactory, task)

     *
     * @return The outputs. Never returns null.
     */
    @Internal
    TaskOutputs getOutputs();

    /**
     * <p>Returns the destroyables of this task.</p>
     * @return The destroyables.  Never returns null.
     *
     * @since 4.0
     */
    @Internal
    TaskDestroyables getDestroyables();

    /**
     * Returns the local state of this task.
     *