XSL-FO pages are filled with content from the <fo:flow> object.
The <fo:flow> object contains all elements to be printed to the page.
When the page is full, the same page master will be used over (and over) again until all the text
The <fo:flow> object has a "flow-name" property that defines where the content
A "real" XSL-FO example:
The output from the code above would be something like this:
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