DirectGUI font?

How can you change the font of a DirectGUI object? I couldn’t find anything in the API documentation…

myfont = loader.loadFont('myfont.ttf')
dl = DirectLabel(font = myfont)

Weird, but

font = loader.loadFont('myfont.ttf') 
text = DirectLabel(text = '', font = font, relief = None, text_fg = (1,1,1,1))
File "C:\Panda3D-1.8.0\direct\gui\DirectGuiBase.py", line 264, in initialiseop
tions
    '" for ' + myClass.__name__
KeyError: 'Unknown option "font" for DirectLabel'

Sorry )
text_font = font