Another config question... :P

Right, I almost got how to use info from the config, but now I am stuck on how to make the plugin to create a new 'section' (I don't know what the word is to describe it ) with custom name. Because this makes absolutely no sense, this is what I am talking about.

Code:

---
playername:
  worldname: 9
anotherplayer:
  worldname: 20
...

So I know how to retrieve them, but I can't figure out how to make plugin to create a new 'section' named after a player name and a world name. ($this->yml->setNested("$name.$world", $health); is the method I use) I have noticed that EconomyAPI have managed to do this, but the code is just too much for me.
Just in case you need some info for this plugin, it is a plugin to set a players' health per world. I might release it here.

If $this->yml is your config:
$this->yml->setNested($name . '.' . $world, $health);

Uh... I guess this is kinda bumping, but it didn't create another section for me

after Config::setNested() you must save it Config::save().