code: def get(self, filepath):
          
          contents = self.get_argument('contents', False)
          if contents == u'true':
              contents = True
          else:
              contents = False
          dir_sizes = self.get_argument('dir_sizes', False)
          if dir_sizes == u'true':
              dir_sizes = True
          else:
              dir_sizes = False
  
          try:
              res = self.fs.get_directory_details(filepath,contents=contents,dir_sizes=dir_sizes)
              res = res.to_dict()
              self.write(res)
          except OSError:
              raise tornado.web.HTTPError(404)
docs: Get directory details for the specified file. If contents is
          set to True (default) then the directory contents will be sent
          along with the directory details. If dir_size is set to True
          (default=False) then du -hs will be run against subdirectories
          for accurate content sizes.