/usr/lib/libdolphinprivate4.so.4 is in dolphin4 4:15.12.3-0ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/libdolphinprivate4.so.4.14.16
/usr/lib/libdolphinprivate4.so.4.14.16