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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 _task_file_exists(self, task_fs):
 """ Returns true if a task file exists in this directory """

        for filename in ["task.{}".format(ext) for ext in self.get_available_task_file_extensions()]:
            if task_fs.exists(filename):
                return True
        return False