@Override
  protected ReadableByteChannel open(ClassLoaderResourceId resourceId) throws IOException {
    ClassLoader classLoader = getClass().getClassLoader();
    InputStream inputStream =
        classLoader.getResourceAsStream(resourceId.path.substring(PREFIX.length()));
    if (inputStream == null) {

      throw new IOException(
          "Unable to load "
              + resourceId.path
              + " with "
              + classLoader
              + " URL "
              + classLoader.getResource(resourceId.path.substring(PREFIX.length())));
    }
    return Channels.newChannel(inputStream);
  }
@Test
  public void testOpen() throws IOException {
    ClassLoaderFileSystem filesystem = new ClassLoaderFileSystem();
    ReadableByteChannel channel = filesystem.open(filesystem.matchNewResource(SOME_CLASS, false));
    checkIsClass(channel);
  }