code: def _check_metrics(self, metrics, params={}):
      self.assertAlmostEquals(
          metrics["rmse"],
          0,
          delta=1e-5,
          msg="Failed case %s. Results %s" % (params, metrics),
      )
      self.assertAlmostEquals(
          metrics["max_error"],
          0,
          delta=1e-5,
          msg="Failed case %s. Results %s" % (params, metrics),
      )
  
imports: import unittest
  import pandas
  import itertools
  import pytest
  from coremltools._deps import _HAS_SKLEARN, _HAS_XGBOOST
  from coremltools.models.utils import evaluate_regressor, _macos_version, _is_macos
label_desc: Use image node_id 2 for calling the GradientBoostingRegressorBostonHousingScikitNumericTest obj's underlying member method code with example usage: obj._check_metrics(metrics, params) without return types