class_docstr: Reports F1 Score for a target class.
code: def result(self) -> tf.Tensor:
      return super().result()[self.target_class]
  
imports: import os
  import tempfile
  from typing import Callable, Optional, Tuple, Type, Union
  from absl import logging
  import ml_collections
  import numpy
  import tensorflow
  import tensorflow_addons
  from deepvariant import dv_constants
  from deepvariant import dv_utils
label_desc: Use image node_id 2 for calling the F1ScorePerClass obj's underlying member method code with example usage: obj.result() and returns: super