class_docstr: Defines the interface for TF metrics.
code: def __init__(self, name, prefix="Metrics"):
      super(TFStepMetric, self).__init__(name)
      common.check_tf1_allowed()
      self._prefix = prefix
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  import tensorflow
  from tf_agents.utils import common
label_desc: Use image node_id 1 to create a new TFStepMetric object from inherited base classes: tf with example: obj = TFStepMetric(name, prefix)