First file in Java lib :'(

src/main/java/leon/codegen/runtime/Tuple.java

+package leon.codegen.runtime;
+
+import java.util.Arrays;
+
+public final class Tuple {
+  private int arity;
+  private Object[] elements;
+
+  public Tuple(int arity, Object[] elements) {
+    this.arity = arity;
+    this.elements = Arrays.copyOf(elements, elements.length);
+  }
+
+  public final Object get(int index) {
+    if(index < 0 || index >= arity) {
+        throw new IllegalArgumentException("Invalid tuple index : " + index);
+    }
+    return this.elements[index];
+  }
+}