/usr/share/jetty9/lib/websocket/javax-websocket-client-impl-9.2.23.v20171218.jar is in jetty9 9.2.23-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/jetty9/lib/websocket/../../../java/jetty9-websocket-client-impl.jar