private InternalIdeaContentRoot readContentRoot(IonReader reader) {
    if (reader.next() == null) return null;
    reader.stepIn();
    InternalIdeaContentRoot contentRoot = new InternalIdeaContentRoot(myReadContext.myGradleVersionComparator);
    contentRoot.setRootDirectory(readFile(reader, "rootDirectory"));
    contentRoot.setSourceDirectories(readSourceDirectories(reader, "sourceDirectories"));
    contentRoot.setTestDirectories(readSourceDirectories(reader, "testDirectories"));
    contentRoot.setResourceDirectories(readSourceDirectories(reader, "resourceDirectories"));
    contentRoot.setTestResourceDirectories(readSourceDirectories(reader, "testResourceDirectories"));
    contentRoot.setExcludeDirectories(readFileSet(reader, "excludeDirectories"));
    reader.stepOut();
    return contentRoot;
  }
private InternalIdeaContentRoot readContentRoot(IonReader reader)