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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def update_image_digest(self, image, platform, digest):
 """Update parent image digest for specific platform :param ImageName image: image """

        image_name_tag = self._key(image)

        image_name = image.to_str(tag=False)
        name_digest = '{}@{}'.format(image_name, digest)

        image_digests = self._images_digests.setdefault(image_name_tag, {})
        image_digests[platform] = name_digest