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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _build_scale_offset(self, dtype):
 """Sets up optional scale and offset factors."""


    # tf.nn.fused_batch_norm accepts float16 batch data, but not scale/offset.
    if self._fused and dtype == tf.float16:
      dtype = tf.float32

    # The fused batch norm operation needs the beta, gamma variables,
    # so in this case we build them and set the trainable option according
    # to the values of _offset and _scale.
    self._beta = None
    if self._offset or self._fused:
      if self.BETA not in self._initializers:
        self._initializers[self.BETA] = create_beta_initializer()
      self._beta = tf.get_variable(
          self.BETA,
          dtype=dtype,
          shape=self._mean_shape,
          initializer=self._initializers[self.BETA],
          partitioner=self._partitioners.get(self.BETA, None),
          regularizer=self._regularizers.get(self.BETA, None),
          trainable=self._offset)

    self._gamma = None
    if self._scale or self._fused:
      if self.GAMMA not in self._initializers:
        self._initializers[self.GAMMA] = create_gamma_initializer()
      self._gamma = tf.get_variable(
          self.GAMMA,
          dtype=dtype,
          shape=self._mean_shape,
          initializer=self._initializers[self.GAMMA],
          partitioner=self._partitioners.get(self.GAMMA, None),
          regularizer=self._regularizers.get(self.GAMMA, None),
          trainable=self._scale)