def close(self):
        self.app = None
        self.log = None
        self.cmdobj = None
        #self.loctxmap = None
        self.updateconns = None
        self.changeset = None
Converts the png file at filepath to a data URL.
dataset/ETHPy150Open erkyrath/tworld/lib/two/task.py/Task.close--crossover with--dataset/ETHPy150Open oppia/oppia/utils.py/convert_png_to_data_url