code: def test_MAE(self):
      mae_metric = MAE()
      predict = np.random.random_sample(1000) * 10
      label = np.random.random_sample(1000) * 10
      result = mae_metric(predict, label)
      self.assertEqual(result.metric_name, "mae")
      self.assertAlmostEqual(
          result.result, mean_absolute_error(label, predict), places=7
      )
  
file_path: FATE/python/fate/ml/evaluation/test/test_reg_metric.py
imports: import unittest
  import numpy
  from sklearn.metrics import mean_squared_error, mean_absolute_error, r2_score
  from fate.ml.evaluation.regression import *
label_desc: Use image node_id 3 for calling the TestMetric obj's underlying member method code with example usage: obj.test_MAE() without return types