class_docstr: Defines the interface for TF metrics.
docstr: A function wrapping the implementor-defined call method.
docstr_tok: ["A","function","wrapping","the","implementor-defined","call","method","."]
code: def _update_state(self, *arg, **kwargs):
      """A function wrapping the implementor-defined call method."""
      return self.call(*arg, **kwargs)
  
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 6 for calling the TFStepMetric obj's underlying member method code with example usage: obj._update_state() and returns: self