class_docstr: MovieLens 100K dataset.
  
  MovieLens datasets were collected by the GroupLens Research Project at the University of
  Minnesota. This dataset consists of 100,000 ratings (1-5) from 943 users on 1682 movies. Each
  user has rated at least 20 movies. User and movie information are provided. The data was
  collected through the MovieLens web site (movielens.umn.edu) during the seven-month period from
  September 19th, 1997 through April 22nd, 1998.
  
  Parameters
  ----------
  unpack_user_and_item
      Whether or not the user and item should be extracted from the context and included as extra
      keyword arguments.
  
  References
  ----------
  [^1]: [The MovieLens Datasets: History and Context](http://dx.doi.org/10.1145/2827872)
code: def _iter(self):
      X_y = stream.iter_csv(
          self.path,
          target="rating",
          converters={
              "timestamp": int,
              "release_date": int,
              "age": float,
              "rating": float,
          },
          delimiter="\t",
      )
      if self.unpack_user_and_item:
          for x, y in X_y:
              user = x.pop("user")
              item = x.pop("item")
              yield x, y, {"user": user, "item": item}
      else:
          yield from X_y
  
imports: from __future__ import annotations
  from river import stream
  from .None import base
label_desc: Use image node_id 2 for calling the MovieLens100K obj's underlying member method code with example usage: obj._iter() without return types