'Log the output.'

def log_output(self, format_dict):

    if ('text/plain' not in format_dict):
        return
    if self.shell.logger.log_output:
        self.shell.logger.log_write(format_dict['text/plain'], 'output')
    self.shell.history_manager.output_hist_reprs[self.prompt_count] = format_dict['text/plain']
