'If database output logging is enabled, this saves all the
outputs from the indicated prompt number to the database. It\'s
called by run_cell after code has been executed.
Parameters
line_num : int
The line number from which to save outputs'

def store_output(self, line_num):

    if ((not self.db_log_output) or (line_num not in self.output_hist_reprs)):
        return
    output = self.output_hist_reprs[line_num]
    with self.db_output_cache_lock:
        self.db_output_cache.append((line_num, output))
    if (self.db_cache_size <= 1):
        self.save_flag.set()
