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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 build_bootdisk(self, image, size=10, auto_delete=True):
 """Buid a disk struct. :param image: Base image name. :type image: ``str`` :param size: Persistent disk size. :type size: ``int`` :param auto_delete: Wether to auto delete disk on instance termination. :type auto_delete: ``bool`` """

        if image is None:
            raise ComputeEngineManagerException("Image must not be None.")
        return {
            'boot': True,
            'autoDelete': auto_delete,
            'initializeParams': {
                'sourceImage': "projects/cos-cloud/global/images/{}".format(image),
                'diskSizeGb': size,
            }
        }