def log_images(self, name, images, step=None):
        """Log new images for given name on given step.

        Args:
            name (str): name of the variable (it will be converted to a valid
                tensorflow summary name).
            images (list): list of images to visualize
            step (int): non-negative integer used for visualization
        """
        if isinstance(images, six.string_types):
            raise TypeError('"images" should be a list of ndarrays, got {}'
                            .format(type(images)))

        self._check_step(step)
        tf_name = self._ensure_tf_name(name)

        summary = self._image_summary(tf_name, images, step=step)
        self._log_summary(tf_name, summary, images, step=step)
Log new images for given name on given step.

        Args:
            name (str): name of the variable (it will be converted to a valid
                tensorflow summary name).
            images (list): list of images to visualize
            step (int): non-negative integer used for visualization