code: def prt_details(self, prt=sys.stdout):
          
          prt.write('EVIDENCE CODES:\n')
          for grp, code2nt in self.grp2code2nt.items():
              prt.write('    {GROUP}:\n'.format(GROUP=grp))
              for code, ntd in code2nt.items():
                  prt.write('        {CODE:>3} {NAME}\n'.format(CODE=code, NAME=ntd.name))
docs: Print summary of codes and groups that can be inputs to get_evcodes.