I just installed drush 7 and 8 in their own directory under /usr/bin as drush7, drush8 commands. Now I'm trying to do the same for drush9, but I'm getting a conflict error during the composer download of drush 9. How can I resolve this to only download the 9.x version?
The command I used was: composer require drush/drush:9.*
I got this idea of using all the drush versions from: