docstr: Initializes dataset once per test. All tests in this class will use the same fake dataset.
docstr_tok: ["Initializes","dataset","once","per","test",".","All","tests","in","this","class","will","use","the","same","fake","dataset","."]
code: def setUpClass(cls):
      """Initializes dataset once per test. All tests in this class will use the same fake dataset."""
      # Write a fake dataset to this location
      cls._dataset_dir = mkdtemp("test_metadata_read")
      cls._dataset_url = "file://{}".format(cls._dataset_dir)
      cls._dataset_dicts = create_test_dataset(
          cls._dataset_url, range(ROWS_COUNT)
      )
  
file_path: petastorm/petastorm/tests/test_metadata_read.py
imports: import os
  import unittest
  from shutil import move, rmtree
  from tempfile import mkdtemp
  from petastorm.tests.test_common import create_test_dataset
label_desc: Use image node_id 1 for calling the MetadataUnischemaReadTest obj's underlying member method code with example usage: obj.setUpClass(cls) without return types