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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 remove_diskgroup(cache_disk_id, data_accessibility=True,
                     service_instance=None):
    '''
    Remove the diskgroup with the specified cache disk.

    cache_disk_id
        The canonical name of the cache disk.

    data_accessibility
        Specifies whether to ensure data accessibility. Default value is True.

    service_instance
        Service instance (vim.ServiceInstance) of the vCenter/ESXi host.
        Default is None.

    .. code-block:: bash

        salt '*' vsphere.remove_diskgroup cache_disk_id='naa.000000000000001'
    '''
    log.trace('Validating diskgroup input')
    host_ref = _get_proxy_target(service_instance)
    hostname = __proxy__['esxi.get_details']()['esxi_host']
    diskgroups = \
            salt.utils.vmware.get_diskgroups(host_ref,
                                             cache_disk_ids=[cache_disk_id])
    if not diskgroups:
        raise VMwareObjectRetrievalError(
            'No diskgroup with cache disk id \'{0}\' was found in ESXi '
            'host \'{1}\''.format(cache_disk_id, hostname))
    log.trace('data accessibility = %s', data_accessibility)
    salt.utils.vsan.remove_diskgroup(
        service_instance, host_ref, diskgroups[0],
        data_accessibility=data_accessibility)
    return True