code: def plot_heatmap(df, col1, col2):
      """
      Generates a heatmap to highlight interactions of two parameters specified
      in col1 and col2.
  
      Parameters
      ----------
      df : Pandas dataframe
           Results from Grid or Random Search
      col1 : string; Name of the first parameter
      col2: string; Name of the second parameter
  
      """
      max_scores = df.groupby([col1, col2]).max()
      max_scores = max_scores.unstack()[["mean_test_score"]]
      sns.heatmap(max_scores.mean_test_score, annot=True, fmt=".3g")
  
imports: import seaborn
  import matplotlib.pyplot
  from cuml.internals.safe_imports import cpu_only_import
label_desc: Use image node_id 1 for calling a global function with example usage: plot_heatmap(df, col1, col2) without return types