code: def custom_mae_mm():
      return h2o.upload_custom_metric(
          CustomMaeFunc, func_name="mae", func_file="mm_mae.py"
      )
  
imports: import sys
  import h2o
  from tests import pyunit_utils
  from tests.pyunit_utils import CustomMaeFunc, dataset_prostate
  from h2o.estimators.gbm import H2OGradientBoostingEstimator
label_desc: Use image node_id 1 for calling a global function with example usage: custom_mae_mm() and returns: h2o