sentences:  For example, when Sun once visited him and showed insufficient respect, he had his guards throw Sun on the ground and pound him with sword hilts.Gao Cheng also installed his assistant Cui Jishu (崔季舒, Cui Xian's uncle) as Emperor Xiaojing's secretary, to keep watch on Emperor Xiaojing.Later in 544, Gao Cheng, wanting to stamp out corruption within the imperial administration, empowered Cui Xian and Song Youdao (宋遊道) to investigate high-level officials for corruption.