return this;
    }

    @Override
    public DefaultGradleRunner withTestKitDir(File testKitDir) {
        validateArgumentNotNull(testKitDir, "testKitDir");
        this.testKitDirProvider = new ConstantTestKitDirProvider(testKitDir);
        return this;
    }

    public List<String> getJvmArguments() {
        return jvmArguments;
    }

        def t = thrown(IllegalArgumentException)
        t.message == 'testKitDir argument cannot be null'
    }

    def "can set custom test kit directory"() {
        given:
        def testKitDir = testDirectoryProvider.createDir('some/dir')

        when:
        def runner = createRunner()
            .withProjectDir(workingDir)
            .withTestKitDir(testKitDir)

        then:
        runner.projectDir == workingDir

            allArgs.add(("-D" + DefaultGradleUserHomeScopeServiceRegistry.REUSE_USER_HOME_SERVICES + "=false") as String)
        }
        def gradleRunner = GradleRunner.create()
            .withTestKitDir(testKitDir)
            .withProjectDir(testDirectory)
            .withArguments(allArgs)
            .withDebug(debug)

        gradleProvider.applyTo(gradleRunner)
        gradleRunner
    }

        delegate.withGradleDistribution(distribution)
        return this
    }

    @Override
    SmokeTestGradleRunner withTestKitDir(File testKitDir) {
        delegate.withTestKitDir(testKitDir)
        return this
    }

    @Override
    File getProjectDir() {
        return delegate.getProjectDir()
    }

    @Override

     * <p>
     * The actual contents of this directory are an internal implementation detail and may change at any time.
     *
     * @param testKitDir the TestKit directory
     * @return {@code this}
     * @since 2.7
     */
    public abstract GradleRunner withTestKitDir(File testKitDir);

    /**
     * The directory that the build will be executed in.
     * <p>

* The `org.gradle.testkit.dir` system property;
* The link:{javadocPath}/org/gradle/testkit/runner/GradleRunner.html#withTestKitDir-java.io.File-[GradleRunner.withTestKitDir(file testKitDir)] method.

[[sub:gradle-runner-gradle-version]]
== Setting the Gradle version used to test