def _variance_scale_term(self):
<EOL>c0 = self.total_concentration[..., tf.newaxis]<EOL>return tf.sqrt((<NUM_LIT:1.> + c0 / self.total_count[..., tf.newaxis]) / (<NUM_LIT:1.> + c0))<EOL>
Helper to `_covariance` and `_variance` which computes a shared scale.