import org.gradle.internal.hash.Hasher;

import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import java.util.Objects;

public class ClassImplementationSnapshot extends ImplementationSnapshot {
    private final HashCode classLoaderHash;

    public ClassImplementationSnapshot(String classIdentifier, HashCode classLoaderHash) {
        super(classIdentifier);
        this.classLoaderHash = classLoaderHash;
    }

import org.gradle.internal.snapshot.impl.ClassImplementationSnapshot;
import org.gradle.internal.snapshot.impl.ImplementationSnapshot;

public class ImplementationChanges implements ChangeContainer {
    private final ClassImplementationSnapshot previousImplementation;
    private final ImmutableList<ImplementationSnapshot> previousAdditionalImplementations;
    private final ClassImplementationSnapshot currentImplementation;

        ) == ["One or more additional actions for task ':test' have changed."]
    }

    List<String> changesBetween(
        ClassImplementationSnapshot previousImpl, List<ImplementationSnapshot> previousAdditionalImpls,
        ClassImplementationSnapshot currentImpl, List<ClassImplementationSnapshot> currentAdditionalImpls
    ) {
        def visitor = new CollectingChangeVisitor()
        new ImplementationChanges(

        // Moreover, they need to come from an actual Class, not a lambda, since there isn't a way for a unit of work implementation to be a lambda.
        ClassImplementationSnapshot currentImplementation = Cast.uncheckedNonnullCast(thisExecution.getImplementation());
        ClassImplementationSnapshot previousImplementation = Cast.uncheckedNonnullCast(lastExecution.getImplementation());

            protected ImplementationSnapshot readAdditionalData(String classIdentifier, Decoder decoder) throws Exception {
                HashCode classLoaderHash = hashCodeSerializer.read(decoder);
                return new ClassImplementationSnapshot(classIdentifier, classLoaderHash);
            }

            @Override
            public void writeAdditionalData(Encoder encoder, ImplementationSnapshot implementationSnapshot) throws Exception {

                .orElseGet(() -> new UnknownImplementationSnapshot(classIdentifier, UnknownReason.UNTRACKED_LAMBDA));
        }

        return new ClassImplementationSnapshot(classIdentifier, classLoaderHash);
    }

    protected ImplementationSnapshot(String classIdentifier) {
        this.classIdentifier = classIdentifier;
    }

    public String getClassIdentifier() {

import org.gradle.internal.operations.BuildOperationRunner
import org.gradle.internal.operations.RunnableBuildOperation
import org.gradle.internal.operations.TestBuildOperationRunner
import org.gradle.internal.snapshot.impl.ClassImplementationSnapshot
import org.gradle.internal.snapshot.impl.DefaultValueSnapshotter
import org.gradle.internal.snapshot.impl.ImplementationSnapshot
import org.gradle.internal.work.AsyncWorkTracker
import spock.lang.Specification