code: def get_storer(self, key):
          
          group = self.get_node(key)
          if group is None:
              raise KeyError('No object named {key} in the file'.format(key=key))
  
          s = self._create_storer(group)
          s.infer_axes()
          return s
docs: return the storer object for a key, raise if not in the file