code: def pd_employee_df():
      return pd.DataFrame({"id": [0], "manager_id": [0]})
  
imports: import pandas
  import pytest
  from featuretools import EntitySet
  from featuretools.tests.testing_utils import backward_path, forward_path
label_desc: Use image node_id 12 for calling a global function with example usage: pd_employee_df() and returns: pd