tf.contrib.distributions.BetaWithSoftplusAB.log_prob(value, name='log_prob')
Log probability density/mass function (depending on is_continuous).
Args:
value: float or double Tensor. 
name: The name to give this op. 
Returns:
log_prob: a Tensor of shape sample_shape(x) + self.batch_shape with values of type self.dtype.