code: def get_features(fields):
      qlib.init(
          provider_uri=TestAutoData.provider_uri,
          expression_cache=None,
          dataset_cache=None,
          joblib_backend="loky",
      )
      return D.features(D.instruments("csi300"), fields)
  
file_path: qlib/tests/misc/test_get_multi_proc.py
imports: import unittest
  import qlib
  from qlib.data import D
  from qlib.tests import TestAutoData
  from multiprocessing import Pool
label_desc: Use image node_id 1 for calling a global function with example usage: get_features(fields) and returns: D