code: def get_single(x, idx):
      if isinstance(x, (pd.Series, pd.DataFrame)):
          return x.iloc[idx]
      return x[idx]
  
imports: from io import BytesIO
  from itertools import product
  import warnings
  import numpy
  import pandas
  import pytest
  from numpy.testing import assert_allclose, assert_array_equal
  from statsmodels import tools
  from statsmodels.regression.linear_model import WLS
  from statsmodels.regression.rolling import RollingWLS, RollingOLS
label_desc: Use image node_id 5 for calling a global function with example usage: get_single(x, idx) and returns: x, x