code: def test_yaml(precalculated_catboost_regression_explainer):
      yaml = precalculated_catboost_regression_explainer.to_yaml()
      assert isinstance(yaml, str)
  
imports: import pandas
  import numpy
  from pandas.api.types import is_categorical_dtype, is_numeric_dtype
  import plotly.graph_objs
label_desc: Use image node_id 29 for calling a global function with example usage: test_yaml(precalculated_catboost_regression_explainer) without return types