Find absolute times for all keys.

        Absolute time is stored in the KeyFrame dictionary as the variable
        __abs_time__.

def bake(self):
        """Find absolute times for all keys.

        Absolute time is stored in the KeyFrame dictionary as the variable
        __abs_time__.
        """
        self.unbake()
        for key in self.dct:
            self.get_absolute_time(key)
        self.is_baked = True