消息来源：https://twitter.com/KeithSmithNBA/status/1330686234780446723
内容：
The Detroit Pistons have renounced the free agent rights for Langston
Galloway, John Henson and Brandon Knight.
This was necessary to create the cap space to make the rest of their
offseason moves.
活塞放弃Galloway、Henson and Knight的鸟权，这个动作帮助活塞创造出薪资空间
以便进行剩下的操作
短评或心得：
应该是释放薪资空间后把之前提到的所有操作全部定下来这样