@Test
  public void testTransform() throws Exception {
    Path output = folder.newFolder("output").toPath();

    JavaTransformer transformer = new JavaTransformer();

    val targetClass = this.getClass().getName();
    BooleanHolder holder = new BooleanHolder(false);

    transformer.addTransformer(
        c -> {
          System.out.println(
              "Transforming class: " + c.getName() + " of type " + c.getClass().getSimpleName());
          if (c.getName().equals(targetClass)) {
            holder.value = true;
          }
        });

    transformer.transform(input, output);

    Assert.assertTrue("Transformer must process " + targetClass, holder.value);

    Assert.assertTrue(exists(output.resolve("me/nallar/javatransformer/api/JavaTransformerTest.")));
  }
 private static Path getClassPath() {
   return JavaTransformer.pathFromClass(JavaTransformerTest.class);
 }