code: public static VirtualFile getChild(URI uri) {
          String path = uri.getPath();
          if(path == null) {
              path = uri.getSchemeSpecificPart();
          }
          return getChild(path);
      }
docs: Find a virtual file.
  
  @param uri the URI whose path component is the child path
  @return the child
  @throws IllegalArgumentException if the path is null