code: def neg(x):
      return -1 * x
  
file_path: ipyparallel/ipyparallel/tests/test_joblib.py
imports: import warnings
  from unittest import mock
  import pytest
  import ipyparallel
  from .clienttest import ClusterTestCase, add_engines
label_desc: Use image node_id 1 for calling a global function with example usage: neg(x) and returns: unknown