code: public LaContainer include(LaContainer parent, String path) {
          final String realPath = pathResolver.resolvePath(parent.getPath(), path);
          assertCircularInclude(parent, realPath);
          enter(realPath);
          try {
              final LaContainer root = parent.getRoot();
              final LaContainer child;
              synchronized (root) {
                  if (root.hasDescendant(realPath)) {
                      showReadingLog(parent, path, realPath, true);
                      child = root.getDescendant(realPath);
                      parent.include(child);
                  } else {
                      showReadingLog(parent, path, realPath, false);
                      final String ext = getExtension(realPath);
                      final LaContainerBuilder builder = getBuilder(ext);
                      child = builder.include(parent, realPath);
                      root.registerDescendant(child);
                      if (child.isInitializeOnCreate()) {
                          child.init();
                      }
                  }
              }
              return child;
          } finally {
              leave(realPath);
          }
      }
docs: =======