@@ -0,0 +1,178 @@
+package hk.hku.cs.f2j;%0A%0Apublic class Tuple2%7B%0A%09public final Object fst;%0A%09public final Object snd;%0A%0A%09public Tuple2(Object fst, Object snd)%7B%0A%09%09this.fst = fst;%0A%09%09this.snd = snd;%0A%09%7D%0A%7D

add Tuple2.java to runtime