def _validateCurrentSentence(self):
        """
        Tests if a sentence contains a valid fix.
        """
        if (self.currentSentence.fixQuality is GPGGAFixQualities.INVALID_FIX
            or self.currentSentence.dataMode is GPGLLGPRMCFixQualities.VOID
            or self.currentSentence.fixType is GPGSAFixTypes.GSA_NO_FIX):
            raise base.InvalidSentence("bad sentence")

        Tests if a sentence contains a valid fix.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/positioning/nmea.py