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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_container_vm(self, container, disk, zone="us-east1-b", tags=None, preemptible=True):
 """Build kwargs for a container VM. :param container: Container declaration. :type container: ``dict`` :param disk: Disk definition structure. :type disk: ``dict`` :param zone: The zone in which the instance should run. :type zone: ``str`` :param tags: Tags associated with the instance. :type tags: ``dict`` :param preemptible: Wether the instance is a preemtible or not. :type preemptible: ``bool`` """

        if tags is None:
            tags = []
        if container is None:
            raise ComputeEngineManagerException("Container declaration must not be None.")
        if disk is None:
            raise ComputeEngineManagerException("Disk structure must not be None.")
        return {
            'ex_metadata': {
                "gce-container-declaration": container,
                "google-logging-enabled": "true"
            },
            'location': zone,
            'ex_tags': tags,
            'ex_disks_gce_struct': [disk],
            'ex_preemptible': preemptible
        }