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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 _rpt_unused_sections(self, prt):
 """Report unused sections."""

        sections_unused = set(self.sections_seen).difference(self.section2goids.keys())
        for sec in sections_unused:
            prt.write("  UNUSED SECTION: {SEC}\n".format(SEC=sec))