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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def calculate_input(self, buffer):
 """ Calculate how many keystrokes were used in triggering this phrase. """

        # TODO: This function is unused?
        if TriggerMode.ABBREVIATION in self.modes:
            if self._should_trigger_abbreviation(buffer):
                if self.immediate:
                    return len(self._get_trigger_abbreviation(buffer))
                else:
                    return len(self._get_trigger_abbreviation(buffer)) + 1

        # TODO - re-enable me if restoring predictive functionality
        #if TriggerMode.PREDICTIVE in self.modes:
        #    if self._should_trigger_predictive(buffer):
        #        return ConfigManager.SETTINGS[PREDICTIVE_LENGTH]

        if TriggerMode.HOTKEY in self.modes:
            if buffer == '':
                return len(self.modifiers) + 1

        return self.parent.calculate_input(buffer)