when:
        scanner.run()

        then:
        1 * detector.startDetection(processor)
        then:
        1 * files.visit(_) >> { args ->
            FileVisitor visitor = args[0]
            assert visitor
            visitor.visitFile(class1)
            visitor.visitFile(class2)
        }
        then:

        class1.add(method1)
        class1.add(method2)
        def class2 = new TestClassResult(2, 'Class2', 5678)
        def results = [class1, class2]

        when:
        def read = serialize(results)

        then:
        read.size() == 2
        def readClass1 = read[0]
        readClass1.className == 'Class1'
        readClass1.startTime == 1234

import spock.lang.Specification

class FilteringClassLoaderSpecSerializerTest extends Specification {
    def serializer = new FilteringClassLoaderSpecSerializer()
    def outputStream = new ByteArrayOutputStream()
    def encoder = new KryoBackedEncoder(outputStream)

    def "can serialize and deserialize a spec"() {
        def classNames = [ 'allowed.Class1', 'allowed.Class2' ]

    private static testClass() {
        """
            package org.gradle.ruleusing;
            public class Class2 extends Class1 { }
        """
    }

    private static classReferencingIntermediate() {
        """
        package org.gradle.ruleusing;
        public class Class1 {
            private org.gradle.intermediate.IntermediateClass mClass = null;
        }
       """
    }

Illustration of Jar instrumentation is shown below.

```mermaid
flowchart TB
    jar(Jar)
    modifiedJar(Jar*)
    class1("Class1")
    class2("Class2")
    class3("Class3")
    modifiedClass1("Class1*")
    modifiedClass2("Class2*")
    modifiedClass3("Class3*")
    instrumentingClassTransform{{"InstrumentingClassTransform\n(ClassVisitor)"}}
    interceptors(Generated interceptors)

    abstract class Class2 extends Class1 implements Interface12 {}
    abstract class Class3<T> extends Class2 implements Interface3<T> {}
    TypeToken<Class3<String>>.TypeSet types = new TypeToken<Class3<String>>() {}.getTypes();
    makeUnmodifiable(types.rawTypes())
        .containsExactly(
            Class3.class,
            Interface3.class,
            Iterable.class,
            Class2.class,

        TestDomainObject value2 = new TestDomainObject('a')
        repository.put('class1', value1)
        repository.put('class2', value2)
        Closure cl = Mock()

        when:
        repository.each(cl)

        then:
        1 * cl.call(['class1', value1] as Object[])
        1 * cl.call(['class2', value2] as Object[])
        0 * cl._
    }

    def canIterateOverClassesUsingAction() {

    abstract class Class2 extends Class1 implements Interface12 {}
    abstract class Class3<T> extends Class2 implements Interface3<T> {}
    TypeToken<Class3<String>>.TypeSet types = new TypeToken<Class3<String>>() {}.getTypes();
    makeUnmodifiable(types.rawTypes())
        .containsExactly(
            Class3.class,
            Interface3.class,
            Iterable.class,
            Class2.class,

        then:
        decodedClassloaderStructure == classLoaderStructure
    }

    def filteringClassloaderSpec() {
        def classNames = [ 'allowed.Class1', 'allowed.Class2' ]
        def disallowedClassNames = [ 'disallowed.Class1', 'disallowed.Class2' ]
        def packagePrefixes = [ 'allowed.pkgprefix1.', 'allowed.pkgprefix2' ]
        def disallowedPackagePrefixes = [ 'disallowed.pkgprefix1.', 'disallowed.pkgprefix2.' ]

        decodedSpec.internalServicesRequired
    }

    def filteringClassloaderSpec() {
        def classNames = [ 'allowed.Class1', 'allowed.Class2' ]
        def disallowedClassNames = [ 'disallowed.Class1', 'disallowed.Class2' ]
        def packagePrefixes = [ 'allowed.pkgprefix1.', 'allowed.pkgprefix2' ]
        def disallowedPackagePrefixes = [ 'disallowed.pkgprefix1.', 'disallowed.pkgprefix2.' ]