code: def test_argmaxn(self):
      ind = argmaxn(self.value_lists, 3)
      assert_equal(len(ind), 3)
  
      ind = argmaxn(self.value_lists, 3)
      assert_equal(np.sum(ind), np.sum([4, 6, 9]))
  
      ind = argmaxn(self.value_lists, 3, order="asc")
      assert_equal(np.sum(ind), np.sum([3, 7, 8]))
  
      with assert_raises(ValueError):
          argmaxn(self.value_lists, -1)
      with assert_raises(ValueError):
          argmaxn(self.value_lists, 20)
  
imports: import os
  import sys
  import unittest
  from numpy.testing import assert_allclose
  from numpy.testing import assert_equal
  from numpy.testing import assert_raises
  from sklearn.metrics import precision_score
  from sklearn.utils import check_random_state
  import numpy
  from utils.utility import standardizer
  from utils.utility import get_label_n
  from utils.utility import precision_n_scores
  from utils.utility import argmaxn
  from utils.utility import invert_order
  from utils.utility import check_detector
  from utils.utility import score_to_label
  from utils.utility import list_diff
  from utils.utility import score_to_proba
label_desc: Use image node_id 9 for calling the TestMetrics obj's underlying member method code with example usage: obj.test_argmaxn() without return types