'Shortcut method to retrieve a specific image (AMI).
:type image_id: string
:param image_id: the ID of the Image to retrieve
:type dry_run: bool
:param dry_run: Set to True if the operation should not actually run.
:rtype: :class:`boto.ec2.image.Image`
:return: The EC2 Image specified or None if the image is not found'

def get_image(self, image_id, dry_run=False):

    try:
        return self.get_all_images(image_ids=[image_id], dry_run=dry_run)[0]
    except IndexError:
        return None
