code: def print_header(header_info, test_info=None):
      """
      Function to print the header with information of the files
  
      :param header_info: Dictionary with information about dataset or train file
      :type header_info: dict
  
      :param test_info: Dictionary with information about test file
      :type test_info: dict
  
      """
  
      print("[Case Recommender: %s]\n" % header_info["title"])
      print(
          "train data:: %d users and %d items (%d interactions) | sparsity:: %.2f%%"
          % (
              header_info["n_users"],
              header_info["n_items"],
              header_info["n_interactions"],
              header_info["sparsity"],
          )
      )
  
      if test_info is not None:
          print(
              "test data:: %d users and %d items (%d interactions) | sparsity:: %.2f%%\n"
              % (
                  test_info["n_users"],
                  test_info["n_items"],
                  test_info["n_interactions"],
                  test_info["sparsity"],
              )
          )
  
file_path: CaseRecommender/caserec/utils/extra_functions.py
imports: import sys
  import time
label_desc: Use image node_id 4 for calling a global function with example usage: print_header(header_info, test_info) without return types