code: def test_set_params_NA_encoder():
      """Test set_params method of NA_encoder class."""
      encoder = NA_encoder()
  
      encoder.set_params(numerical_strategy="mean")
      assert encoder.numerical_strategy == "mean"
      encoder.set_params(numerical_strategy="median")
      assert encoder.numerical_strategy == "median"
      encoder.set_params(numerical_strategy="most_frequent")
      assert encoder.numerical_strategy == "most_frequent"
      encoder.set_params(numerical_strategy=3.0)
      assert encoder.numerical_strategy == 3.0
  
      encoder.set_params(categorical_strategy="<NULL>")
      assert encoder.categorical_strategy == "<NULL>"
      encoder.set_params(categorical_strategy="most_frequent")
      assert encoder.categorical_strategy == "most_frequent"
      encoder.set_params(categorical_strategy="string_test")
      assert encoder.categorical_strategy == "string_test"
  
      with pytest.warns(UserWarning) as record:
          encoder.set_params(_Categorical_encoder__Lcat=[])
      assert len(record) == 1
  
file_path: MLBox/tests/test_na_encoder.py
imports: import pytest
  import pandas
  from mlbox.encoding.na_encoder import NA_encoder
label_desc: Use image node_id 3 for calling a global function with example usage: test_set_params_NA_encoder() without return types