def METHOD_NAME(self):
    self.completions = {
        'AnElement':(
            ['plotoptA1', 'plotoptA2'],
            ['styleoptA1', 'styleoptA2']),
        'AnotherElement':(
            ['plotoptB1', 'plotoptB2'],
            ['styleoptB1', 'styleoptB2']),
        'BarElement':(
            ['plotoptC1', 'plotoptC2'],
            ['styleoptC1', 'styleoptC2'])}
    self.compositor_defs = {}
    self.all_keys = sorted(self.completions.keys()) + ['style(', 'plot[', 'norm{']
    super().METHOD_NAME()