networks: Streamline print-org-tbfs/state.

networks.rkt

@@ -1146,15 +1146,13 @@
 ;;; names of the variables, as well as the symbol 'θ to represent the
 ;;; column giving the thresholds of the TBF.
 (define (print-org-tbfs/state tbfs #:headers [headers #t])
-
   (define table (for/list ([tbf (in-list tbfs)])
                   (append (hash-map (tbf/state-w tbf) (λ (_ w) w) #t)
                           (list (tbf/state-θ tbf)))))
-  (append
-   (if headers
-       (list (append (hash-map (tbf/state-w (car tbfs)) (λ (x _) x) #t) '(θ)))
-       (empty))
-   table))
+  (if headers
+      (cons (append (hash-map (tbf/state-w (car tbfs)) (λ (x _) x) #t) '(θ))
+            table)
+      table))
 
 (module+ test
   (test-case "print-org-tbfs/state"