Process a list of `texts`.

def process_all(self, texts:Collection[str]) -> List[List[str]]:
        "Process a list of `texts`."
        if self.n_cpus <= 1: return self._process_all_1(texts)
        with ProcessPoolExecutor(self.n_cpus) as e:
            return sum(e.map(self._process_all_1, partition_by_cores(texts, self.n_cpus)), [])