code: def test_dimensions(dataset):
      n = 0
      for x, _ in dataset:
          if not dataset.sparse:
              assert len(x) == dataset.n_features
          n += 1
      assert n == dataset.n_samples
  
file_path: river/river/datasets/test_datasets.py
imports: from __future__ import annotations
  import functools
  import importlib
  import inspect
  import itertools
  from urllib import request
  import pytest
  from river import datasets
  from .None import base
label_desc: Use image node_id 3 for calling a global function with example usage: test_dimensions(dataset) without return types