def exec_(self, source):
        if not self.is_available():
            raise execjs.RuntimeUnavailableError
        return self._exec_(source)
If a request is made with an I{If-Modified-Since} header value which
dataset/ETHPy150Open doloopwhile/PyExecJS/execjs/_abstract_runtime_context.py/AbstractRuntimeContext.exec_--crossover with--dataset/ETHPy150Open kuri65536/python-for-android/python-modules/twisted/twisted/web/test/test_web.py/ConditionalTest.test_invalidTimestamp