docs: public static void waitForProcessOutput(Process self, Appendable output, Appendable error) {
          Thread tout = consumeProcessOutputStream(self, output);
          Thread terr = consumeProcessErrorStream(self, error);
          try { tout.join(); } catch (InterruptedException ignore) {}
          try { terr.join(); } catch (InterruptedException ignore) {}
          try { self.waitFor(); } catch (InterruptedException ignore) {}
          closeStreams(self);
      }