human
Complete the below
def _get_device_template(disk, disk_info, template=None):

    ''''Returns the template format to create a disk in open nebula
    .. versionadded:: oxygen'
    '''

=====
Can you provide a the Python program you requested?
assistant
#Here is the Python program you requested.
    def _require_disk_opts(*args):
        for arg in args:
            if (arg not in disk_info):
                raise SaltCloudSystemExit('The    disk    {0}    requires    a    {1}                                                                                argument'.format(disk, arg))
    _require_disk_opts('disk_type', 'size')
    size = disk_info['size']
    disk_type = disk_info['disk_type']
    if (disk_type == 'clone'):
        if ('image' in disk_info):
            clone_image = disk_info['image']
        else:
            clone_image = get_template_image(kwargs={'name': template})
        clone_image_id = get_image_id(kwargs={'name': clone_image})
        temp = 'DISK=[IMAGE={0},    IMAGE_ID={1},    CLONE=YES,                                                                                                SIZE={2}]'.format(clone_image, clone_image_id, size)
        return temp
    if (disk_type == 'volatile'):
        _require_disk_opts('type')
        v_type = disk_info['type']
        temp = 'DISK=[TYPE={0},    SIZE={1}]'.format(v_type, size)
        if (v_type == 'fs'):
            _require_disk_opts('format')
            format = disk_info['format']
            temp = 'DISK=[TYPE={0},    SIZE={1},    FORMAT={2}]'.format(v_type, size, format)
        return temp