/usr/lib/libreoffice/sdk/classes/ is in libreoffice-dev-common 1:6.0.3-0ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/libreoffice/sdk/classes/com/
/usr/lib/libreoffice/sdk/classes/com/sun/
/usr/lib/libreoffice/sdk/classes/com/sun/star/
/usr/lib/libreoffice/sdk/classes/com/sun/star/lib/
/usr/lib/libreoffice/sdk/classes/com/sun/star/lib/loader/
/usr/lib/libreoffice/sdk/classes/com/sun/star/lib/loader/InstallationFinder$StreamGobbler.class
/usr/lib/libreoffice/sdk/classes/com/sun/star/lib/loader/InstallationFinder.class
/usr/lib/libreoffice/sdk/classes/com/sun/star/lib/loader/Loader$1.class
/usr/lib/libreoffice/sdk/classes/com/sun/star/lib/loader/Loader$CustomURLClassLoader.class
/usr/lib/libreoffice/sdk/classes/com/sun/star/lib/loader/Loader$Drain.class
/usr/lib/libreoffice/sdk/classes/com/sun/star/lib/loader/Loader.class
/usr/lib/libreoffice/sdk/classes/com/sun/star/lib/loader/WinRegKey.class
/usr/lib/libreoffice/sdk/classes/com/sun/star/lib/loader/WinRegKeyException.class
/usr/lib/libreoffice/sdk/classes/win/
/usr/lib/libreoffice/sdk/classes/win/unowinreg.dll