'Get the role played by the image, based on its type.'

@classmethod
def get_role(cls, image_type_id):

    return {cls.KERNEL: 'kernel', cls.RAMDISK: 'ramdisk', cls.DISK: 'root', cls.DISK_RAW: 'root', cls.DISK_VHD: 'root', cls.DISK_ISO: 'iso', cls.DISK_CONFIGDRIVE: 'configdrive'}.get(image_type_id)
