code: def test_build_full_trainset(toy_data):
      """Test the build_full_trainset method."""
  
      trainset = toy_data.build_full_trainset()
  
      assert len(trainset.ur) == 5
      assert len(trainset.ir) == 2
      assert trainset.n_users == 5
      assert trainset.n_items == 2
  
file_path: Surprise/tests/test_dataset.py
imports: import os
  import random
  import pandas
  import pytest
  from surprise import BaselineOnly, Dataset, Reader
  from surprise.builtin_datasets import get_dataset_dir
  from surprise.model_selection import KFold, PredefinedKFold
label_desc: Use image node_id 2 for calling a global function with example usage: test_build_full_trainset(toy_data) without return types