'This method is called once at viewer startup. It should load any fonts
it wants to make available. For example::
def load_fonts():
from PyQt5.Qt import QFontDatabase
font_data = get_resources([\'myfont1.ttf\', \'myfont2.ttf\'])
for raw in font_data.itervalues():
QFontDatabase.addApplicationFontFromData(raw)'

def load_fonts(self):

    pass
