Work on RequestManager, a new way to create and manage requests.

src/main/java/com/alttd/util/Pair.java

@@ -0,0 +1,21 @@
+package com.alttd.util;
+
+public class Pair<X, Y> {
+
+    private final X x;
+    private final Y y;
+
+    public Pair(X x, Y y) {
+        this.x = x;
+        this.y = y;
+    }
+
+    public X getValue0() {
+        return x;
+    }
+
+    public Y getValue1() {
+        return y;
+    }
+}
+