code: def __str(self, quote=False, prefix="", suffix=""):
          
          quotes = '"%s"'
          pstr = "dry_run=%s, " % self._dry_run
  
          kmods = self._kmods
          kmods = [quotes % k for k in kmods] if quote else kmods
          pstr += "kmods=[%s], " % (",".join(kmods))
  
          services = self._services
          services = [quotes % s for s in services] if quote else services
          pstr += "services=[%s]" % (",".join(services))
  
          return prefix + pstr + suffix
docs: Return a string representation of this SoSPredicate with
              optional prefix, suffix and value quoting.