fluente spelling

Hello!

I have a model with several public methods.
These methods have

return $ this;

In the controller I want to call these methods in the fluents spelling.
For example.

----------- my controller -----------------

$namePdfRechnung = $model_pdf
                    ->setDaten($model_kundendatenUndBuchungsdaten)
                    ->setSchriften($fontTexte)
                    ->erstellenPdfSpalten()  // navigation don't work
                    ->setBuchungsnummer()
                    ->erstellenGrunddokument()
                    ->erstellenRechnungsblock()
                    ->erstellenInformationen()
                    ->speichernPdf(); // abspeichern Pdf



-------------------------------------

The Naviagtion in these methods with 'Ctrl' and 'mouseover'
works up to the 2nd Method. Who can help with information.

Sincerely yours

Stephan