code: public static void setGroup(FileSystem fs, Path path, String group) throws IOException {
      fs.setOwner(path, fs.getFileStatus(path).getOwner(), group);
    }
docs: Set the group associated with a given path.
  
  @param fs the {@link FileSystem} instance used to perform the file operation
  @param path the given path
  @param group the group associated with the path
  @throws IOException