/usr/lib/ruby/2.3.0/tkscrollbox.rb is in ruby2.3-tcltk 2.3.3-1+deb9u2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 | # frozen_string_literal: false
#
# tkscrollbox.rb - load tk/scrollbox.rb
#
require 'tk/scrollbox'
|