class_docstr: Compute Harmonic Mean
  The harmonic mean is a kind of mean. It can be expressed as the reciprocal of
  the arithmetic mean of the reciprocals of the given set of numbers.
  Note: `tfa.metrics.HarmonicMean` can be used the same as `tf.keras.metrics.Mean`.
  Args:
      name: (Optional) String name of the metric instance.
      dtype: (Optional) Data type of the metric result.
  Usage:
  >>> metric = tfa.metrics.HarmonicMean()
  >>> metric.update_state([1, 4, 4])
  >>> metric.result().numpy()
  2.0
code: def update_state(self, values, sample_weight=None) -> None:
      values = tf.cast(values, dtype=self.dtype)
      super().update_state(tf.math.reciprocal(values), sample_weight)
  
file_path: addons/tensorflow_addons/metrics/harmonic_mean.py
imports: import tensorflow
  from typeguard import typechecked
  from tensorflow_addons.utils.types import AcceptableDTypes
label_desc: Use image node_id 2 for calling the HarmonicMean obj's underlying member method code with example usage: obj.update_state(values, sample_weight) without return types