then:
        _ * work.visitImplementations(_) >> { UnitOfWork.ImplementationVisitor visitor ->
            visitor.visitImplementation(implementationSnapshot)
            additionalImplementations.each {
                visitor.visitImplementation(it)
            }
        }
        interaction { snapshotState() }
        1 * delegate.execute(work, _ as BeforeExecutionContext) >> { UnitOfWork work, BeforeExecutionContext delegateContext ->

                        @Override
                        public UnitOfWork.Identity getIdentity() {
                            return identity;
                        }
                    });
            }
        });
    }

    private static Result executeInternal(UnitOfWork work, InputChangesContext context) {
        UnitOfWork.ExecutionRequest executionRequest = new UnitOfWork.ExecutionRequest() {
            @Override

import com.google.common.collect.ImmutableSortedMap;
import org.gradle.internal.execution.InputFingerprinter;
import org.gradle.internal.execution.UnitOfWork;
import org.gradle.internal.execution.UnitOfWork.InputFileValueSupplier;
import org.gradle.internal.execution.UnitOfWork.InputVisitor;
import org.gradle.internal.execution.WorkInputListeners;
import org.gradle.internal.fingerprint.CurrentFileCollectionFingerprint;

        when:
        def result = step.execute(work, context)

        then:
        result == delegateResult

        _ * work.executionBehavior >> UnitOfWork.ExecutionBehavior.NON_INCREMENTAL
        1 * delegate.execute(work, _ as IncrementalChangesContext) >> { UnitOfWork work, IncrementalChangesContext delegateContext ->
            def changes = delegateContext.changes.get()

     */
    protected abstract Optional<HashCode> getPreviousCacheKeyIfApplicable(C context);

    protected abstract UpToDateResult executeDelegate(UnitOfWork work, C context, CachingState cachingState);

    private CachingState calculateCachingStateWithNoCapturedInputs(UnitOfWork work) {
        if (!buildCache.isEnabled()) {
            return BUILD_CACHE_DISABLED_STATE;
        }
        return work.shouldDisableCaching(null)

        when:
        def result = outputSnapshotter.snapshotOutputs(work, workspace)

        then:
        1 * work.visitOutputs(workspace, _ as UnitOfWork.OutputVisitor) >> { File workspace, UnitOfWork.OutputVisitor outputVisitor ->
            outputVisitor.visitOutputProperty("output", TreeType.FILE, UnitOfWork.OutputFileValueSupplier.fromStatic(root, contents))
        }

import static org.gradle.internal.execution.ExecutionEngine.ExecutionOutcome.UP_TO_DATE
import static org.gradle.internal.execution.UnitOfWork.WorkResult.DID_NO_WORK
import static org.gradle.internal.execution.UnitOfWork.WorkResult.DID_WORK

class ExecuteStepTest extends StepSpec<ChangingOutputsContext> {
    def workspace = Mock(File)
    def previousOutputs = ImmutableSortedMap.of()

        then:
        _ * work.visitOutputs(_ as File, _ as UnitOfWork.OutputVisitor) >> { File workspace, UnitOfWork.OutputVisitor visitor ->
            visitor.visitOutputProperty("dir", TreeType.DIRECTORY, UnitOfWork.OutputFileValueSupplier.fromStatic(outputDir, TestFiles.fixed(outputDir)))
            visitor.visitOutputProperty("file", TreeType.FILE, UnitOfWork.OutputFileValueSupplier.fromStatic(outputFile, TestFiles.fixed(outputFile)))

        context.getPreviousExecutionState().ifPresent(previousOutputs -> {
            Set<File> outputDirectoriesToPreserve = new HashSet<>();
            work.visitOutputs(context.getWorkspace(), new UnitOfWork.OutputVisitor() {
                @Override
                public void visitOutputProperty(String propertyName, TreeType type, UnitOfWork.OutputFileValueSupplier value) {

import org.gradle.internal.Deferrable;
import org.gradle.internal.Try;
import org.gradle.internal.execution.ExecutionEngine.IdentityCacheResult;
import org.gradle.internal.execution.UnitOfWork;
import org.gradle.internal.execution.UnitOfWork.Identity;
import org.gradle.internal.execution.history.ExecutionOutputState;
import org.gradle.internal.operations.BuildOperationProgressEventEmitter;