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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 output(self, out_file):
 """Write the converted entries to out_file"""

        self.out_file = out_file
        out_file.write('event: ns : Nanoseconds\n')
        out_file.write('events: ns\n')
        self._output_summary()
        for entry in sorted(self.entries, key=_entry_sort_key):
            self._output_entry(entry)