import tensorflow as tf

            labels: (tf.Tensor) A tensor of the same shape as `output`. A value >= 1 means a
            relevant example.
            propensity_weights: (tf.Tensor) A tensor of the same shape as `output` containing the weight of each element. 
            name: A string used as the name for this variable scope.

        Returns:
            (tf.Tensor) A single value tensor containing the loss.
        """
        loss = None
        with tf.name_scope(name, "click_weighted_log_loss",[output]):
            click_prob = tf.sigmoid(output)
            loss = tf.losses.log_loss(labels, click_prob, propensity_weights)
        return loss
