why don't the website of example tell the name of input file?

https://examples.vtk.org/site/Cxx/PolyData/ColorDisconnectedRegionsDemo/
the website contains an example,but it doesn’t describe the name of input file. how do i check the name of input file?

It is footbones.ply.

Tip : Now that almost every C++ example is interactive in the browser, you can discover the data file being used with a trick. Click on the “Interactive example” and open developer console to see which file was loaded under data directory. Remove the .js suffix and you’ve your filename. See the screenshot for reference.

I wonder if it’s possible to automatically find this and show the file name above the viewer. Even better if it could just print all arguments.