class_docstr: Metric object.
class_docstr_tok: ["Metric","object","."]
docstr: String key corresponding to the metric name.
docstr_tok: ["String","key","corresponding","to","the","metric","name","."]
code: def key(self):
      """String key corresponding to the metric name."""
      return self._key
  
file_path: mlflow/mlflow/entities/metric.py
imports: from mlflow.entities._mlflow_object import _MLflowObject
  from mlflow.protos.service_pb2 import Metric
label_desc: Use image node_id 2 for calling the Metric obj's underlying member method code with example usage: obj.key() and returns: self