What's the order of the spaces returned by LabelManager.getSpacesWithLabel(Label label)?

So, in the class LabelManager there is the method getSpacesWithLabel(Label label) and I can’t figure out what’s the criteria for the order of the spaces returned by it. It doesn’t seem to be alphabetical nor related to the last time I accessed each space. I would just like to know what criteria it follows to sort the spaces on the list.

Here is the JavaDoc for the method:
https://docs.atlassian.com/ConfluenceServer/javadoc/7.2.1/com/atlassian/confluence/labels/LabelManager.html#getSpacesWithLabel-com.atlassian.confluence.labels.Label-