/usr/include/log4cplus/helpers/ is in liblog4cplus-dev 1.0.4-1ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/include/log4cplus/helpers/appenderattachableimpl.h
/usr/include/log4cplus/helpers/loglog.h
/usr/include/log4cplus/helpers/logloguser.h
/usr/include/log4cplus/helpers/pointer.h
/usr/include/log4cplus/helpers/property.h
/usr/include/log4cplus/helpers/sleep.h
/usr/include/log4cplus/helpers/socket.h
/usr/include/log4cplus/helpers/socketbuffer.h
/usr/include/log4cplus/helpers/stringhelper.h
/usr/include/log4cplus/helpers/syncprims-pthreads.h
/usr/include/log4cplus/helpers/syncprims.h
/usr/include/log4cplus/helpers/thread-config.h
/usr/include/log4cplus/helpers/threads.h
/usr/include/log4cplus/helpers/timehelper.h