Impossible to use theme from the library

[Techniv]

It's impossible to import material theme from the directly dist/css/themes folder.
I correctly read the documentation that say I need to replace the dist/css/mdDateTimePicker.css with the choosen css theme file.

Note: Since, themes override the default stylesheets, so in order to use a theme just replace your previously used css and min.css files with these files.

This is definitively unacceptable in an industrial context.

Libraries are imported in projects from dependency managers. Modify the content of a library to change a theme is not a valid option.