docs: def write(self, path, data, offset, fh):  # pragma: no cover
          """
          This is a readonly filesystem right now
          """
          # print("write {}".format(path))
          with self.attr_lock:
              base = self.attr[path][BASE_KEY]
              staged = self.attr[path][STAGED_KEY]
              if not staged.closed:
                  base.st_size += len(data)
                  staged.write(data)
          return len(data)