docs: public void computeRemainingTrailers() {
          if (tc.isEntryEnabled()) {
              Tr.entry(tc, "computeRemainingTrailers");
          }
          Iterator<HeaderKeys> knowns = this.knownTGs.keySet().iterator();
          while (knowns.hasNext()) {
              HeaderKeys key = knowns.next();
              setHeader(key, this.knownTGs.get(key).generateTrailerValue(key, this));
          }
          if (tc.isEntryEnabled()) {
              Tr.exit(tc, "computeRemainingTrailers");
          }
      }