fail: add correctly

test/net/m14m/romannumeralkata/AdditionTest.java

@@ -0,0 +1,24 @@
+package net.m14m.romannumeralkata;
+
+import org.junit.*;
+
+import static org.junit.Assert.assertEquals;
+
+public class AdditionTest {
+    @Test public void shouldAddUpNumbersCorrectly() {
+        Addition addition = new Addition(arabicConstant(1), arabicConstant(3));
+        assertEquals(4, addition.getValue());
+    }
+
+    private Expression arabicConstant(final int value) {
+        return new Expression() {
+            public int getValue() {
+                return value;
+            }
+
+            public Formatter getFormatter() {
+                return new ArabicNumeralFormatter();
+            }
+        };
+    }
+}