/usr/include/dcmtk/oflog/helpers/ is in libdcmtk2-dev 3.6.0-15.
This file is owned by root:root, with mode 0o755.
..
/usr/include/dcmtk/oflog/helpers/apndimpl.h
/usr/include/dcmtk/oflog/helpers/lloguser.h
/usr/include/dcmtk/oflog/helpers/loglog.h
/usr/include/dcmtk/oflog/helpers/pointer.h
/usr/include/dcmtk/oflog/helpers/property.h
/usr/include/dcmtk/oflog/helpers/sleep.h
/usr/include/dcmtk/oflog/helpers/sockbuff.h
/usr/include/dcmtk/oflog/helpers/socket.h
/usr/include/dcmtk/oflog/helpers/strhelp.h
/usr/include/dcmtk/oflog/helpers/syncppth.h
/usr/include/dcmtk/oflog/helpers/syncprims.h
/usr/include/dcmtk/oflog/helpers/syncpwin.h
/usr/include/dcmtk/oflog/helpers/threadcf.h
/usr/include/dcmtk/oflog/helpers/threads.h
/usr/include/dcmtk/oflog/helpers/timehelp.h