code: def test_wrappers_pandas_input():
      """Input: DataFrame, Output: DataFrame"""
      # Skip this test if you don't have pandas
      pytest.importorskip("pandas")
      import pandas as pd
  
      # Create a DataFrame with a NaN
      A = np.arange(25).reshape((5, 5)).astype(np.float)
      A[0, 0] = np.nan
      A = pd.DataFrame(A)
      # Assert that the output is a DataFrame
      assert isinstance(mean(A), pd.DataFrame)
  
imports: import pytest
  import numpy
  from impyute.imputation.cs import mean
  from impyute.ops import error
  from impyute.ops import wrapper
label_desc: Use image node_id 4 for calling a global function with example usage: test_wrappers_pandas_input() without return types