docs: def init_datastores(self):
          """Initialize datastores for this analysis instance.
  
          This creates instances of :class:`.Datastore` at ``data`` and
          ``class_data`` with the datastore domains being the current id
          and the class name of this analysis respectively.
  
          Overwrite this method to use other datastore backends.
          """
          self.data = Datastore(self.id_)
          self.data.subscribe(lambda data: self.emit('data', data))
          self.class_data = Datastore(type(self).__name__)
          self.class_data.subscribe(lambda data: self.emit('class_data', data))