code: def test_truncate_str_1(self):
      t = truncate_str(12)
      assert t == 12
  
imports: import unittest
  import numpy
  import pandas
  from shapash.utils.utils import inclusion, within_dict, is_nested_list, compute_digit_number, truncate_str, add_line_break, maximum_difference_sort_value, compute_sorted_variables_interactions_list_indices, compute_top_correlations_features
label_desc: Use image node_id 12 for calling the TestUtils obj's underlying member method code with example usage: obj.test_truncate_str_1() without return types