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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 build_string(self):
 """ Taskcluster denotes builds in one of two formats - i.e. linux64-asan or linux64-asan-opt The latter is generated. If it fails, the caller should try the former. """

        return (('-ccov' if self.coverage else '') +
                ('-fuzzing' if self.fuzzing else '') +
                ('-asan' if self.asan else '') +
                ('-valgrind' if self.valgrind else '') +
                ('-debug' if self.debug else '-opt'))