given:
        def original = jar(testDir.file("original.jar")) {
            manifest {
                multiRelease()
            }

            entry("Foo.class", ORIGINAL_CLASS)
        }

        def transformed = jar(testDir.file("transformed.jar")) {
            manifest {
                multiRelease()
            }

            entry("Foo.class", INSTRUMENTED_CLASS)

     */
    static class ManifestWithDsl extends Manifest {
        /**
         * Configures this Manifest to be Multi-Release.
         */
        void multiRelease() {
            mainAttributes.putValue(JarUtil.MULTI_RELEASE_ATTRIBUTE, "true")
        }
    }

            file("build.gradle") << """
                plugins {
                    id("java")
                    id 'me.champeau.mrjar' version "0.1.1"
                }

                multiRelease {
                    targetVersions 8, 11
                }
            """
            file("src/main/java/org/gradle/test/mrjar/Foo.java") << """
                package org.gradle.test.mrjar;

import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;

public class JarUtil {
    // We cannot use Attributes.Name.MULTI_RELEASE as it is only available since Java 9;
    public static final String MULTI_RELEASE_ATTRIBUTE = "Multi-Release";
    // Pattern for JAR entries in the versioned directories.