Is the "parent" key supported in Drush 9? It isn't in the example file here https://github.com/drush-ops/drush/blob/master/examples/example.site.yml or
drush docs:aliases and I am trying to get a bastion working off of the Drush 8 docs (https://docs.drush.org/en/8.x/bastion/).
Can anyone confirm it should pickup a "parent" key?
edit: I see here http://api.drush.org/api/drush/examples%21example.aliases.drushrc.php/master that "parent" was deprecated before the switch to YAML in Drush 9 so maybe it is called something else now. Not sure how to specify merging key values in YAML.