class_docstr: Metric base class.
class_docstr_tok: ["Metric","base","class","."]
docstr: Updates the metric and returns the new value.
docstr_tok: ["Updates","the","metric","and","returns","the","new","value","."]
code: def __call__(self, value):
      """Updates the metric and returns the new value."""
      self.update(value)
      return self.value
  
imports: import abc
  from typing import Optional
  from sonnet.src import base
  from sonnet.src import once
  import tensorflow
label_desc: Use image node_id 5 for calling the Metric obj's underlying member method code with example usage: obj.__call__(value) and returns: self