val compileKotlinTask = tasks.getByName("compileKotlin") as KotlinJvmCompile
    dependsOn(compileKotlinTask)

    if (enableValidation) {
      compileKotlinTask.source(file("src/main/java9"))
    }

    // Ignore warnings about using 'requires transitive' on automatic modules.
    // not needed when compiling with recent JDKs, e.g. 17
    options.compilerArgs.add("-Xlint:-requires-transitive-automatic")

                <arg>-XDignore.symbol.file</arg>
              </compilerArgs>
            </configuration>
          </execution>
          <execution>
            <id>compile-java9</id>
            <phase>compile</phase>
            <goals>
              <goal>compile</goal>
            </goals>
            <configuration>
              <release>9</release>
              <compileSourceRoots>

  }

  @Test
  public void testMockWebServer() throws IOException {
    MockWebServer server = new MockWebServer();
    server.enqueue(new MockResponse(200, Headers.of(), "Hello, Java9!"));
    server.start();

    // Just check we can run code that depends on OkHttp types
    Call call = OkHttpCaller.callOkHttp(server.url("/"));

    try (Response response = call.execute();) {

                <arg>-XDignore.symbol.file</arg>
              </compilerArgs>
            </configuration>
          </execution>
          <execution>
            <id>compile-java9</id>
            <phase>compile</phase>
            <goals>
              <goal>compile</goal>
            </goals>
            <configuration>
              <release>9</release>

                <arg>-sourcepath</arg>
                <arg>doesnotexist</arg>
              </compilerArgs>
            </configuration>
          </execution>
          <execution>
            <id>compile-java9</id>
            <goals>
              <goal>compile</goal>
            </goals>
            <configuration>
              <release>9</release>
              <compileSourceRoots>