code: def _to_bigdl_metric(metric):
      metric = metric.lower()
      if metric == "accuracy" or metric == "acc":
          return metrics.Accuracy()
      elif metric == "top5accuracy" or metric == "top5acc":
          return metrics.Top5Accuracy()
      elif metric == "mae":
          from bigdl.dllib.optim.optimizer import MAE
  
          return MAE()
      elif metric == "auc":
          return metrics.AUC()
      elif metric == "treennaccuracy":
          return TreeNNAccuracy()
      else:
          invalidInputError(False, "Unsupported metric: %s" % metric)
  
file_path: BigDL/python/orca/src/bigdl/orca/tfpark/estimator.py
imports: from bigdl.dllib.optim.optimizer import MaxIteration, Loss, TreeNNAccuracy
  from bigdl.orca.tfpark.utils import evaluate_string_metrics
  from bigdl.dllib.keras import metrics
  from bigdl.orca.tfpark.tfnet import TFNet
  from bigdl.orca.tfpark.tf_optimizer import TFOptimizer
  from bigdl.orca.tfpark.tf_dataset import TFDataset
  from bigdl.dllib.utils import nest
  import six
  import os
  from bigdl.dllib.utils.log4Error import *
label_desc: Use image node_id 7 for calling the TFEstimator obj's underlying member method code with example usage: obj._to_bigdl_metric(metric) and returns: metrics, metrics, MAE, metrics, TreeNNAccuracy