/usr/lib/nodejs/fstream/ is in node-fstream 1.0.10-1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/nodejs/fstream/fstream.js
/usr/lib/nodejs/fstream/lib/
/usr/lib/nodejs/fstream/lib/abstract.js
/usr/lib/nodejs/fstream/lib/collect.js
/usr/lib/nodejs/fstream/lib/dir-reader.js
/usr/lib/nodejs/fstream/lib/dir-writer.js
/usr/lib/nodejs/fstream/lib/file-reader.js
/usr/lib/nodejs/fstream/lib/file-writer.js
/usr/lib/nodejs/fstream/lib/get-type.js
/usr/lib/nodejs/fstream/lib/link-reader.js
/usr/lib/nodejs/fstream/lib/link-writer.js
/usr/lib/nodejs/fstream/lib/proxy-reader.js
/usr/lib/nodejs/fstream/lib/proxy-writer.js
/usr/lib/nodejs/fstream/lib/reader.js
/usr/lib/nodejs/fstream/lib/socket-reader.js
/usr/lib/nodejs/fstream/lib/writer.js
/usr/lib/nodejs/fstream/package.json