code: public T responseTrailersSanitizer(
              Function<? super HttpHeaders, ? extends HttpHeaders> responseTrailersSanitizer) {
          this.responseTrailersSanitizer = requireNonNull(responseTrailersSanitizer, "responseTrailersSanitizer");
          return self();
      }
docs: Sets the {@link Function} to use to sanitize response trailing headers before logging. If unset,
  will use {@link Function#identity()}.