docstr: Test that the loss is 0 at the true parameters.
docstr_tok: ["Test","that","the","loss","is","0","at","the","true","parameters","."]
code: def test_loss_at_true_is_zero(self, n_samples, atol):
      """Test that the loss is 0 at the true parameters."""
      model = self.data_generator.random_model()
      X, y = model.generate(n_samples)
  
      loss = self.estimator._loss(X, y, model.param)
      self.assertAllClose(loss, 0.0, atol=atol)
  
file_path: geomstats/geomstats/test_cases/learning/geodesic_regression.py
imports: import pytest
  import geomstats.backend
  from geomstats.test.random import RandomDataGenerator
  from geomstats.test_cases.learning._base import BaseEstimatorTestCase
label_desc: Use image node_id 2 for calling the GeodesicRegressionTestCase obj's underlying member method code with example usage: obj.test_loss_at_true_is_zero(n_samples, atol) without return types