diff -r 251d0ed461fb -r 58ec6da75f6f task4/solution02/test/org/apidesign/apifest08/test/Task2Test.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/task4/solution02/test/org/apidesign/apifest08/test/Task2Test.java	Sat Oct 11 23:38:46 2008 +0200
@@ -0,0 +1,119 @@
+package org.apidesign.apifest08.test;
+
+import static org.apidesign.apifest08.currency.ConvertorFactory.createConvertor;
+import static org.apidesign.apifest08.currency.ConvertorFactory.mergeConvertors;
+import static org.apidesign.apifest08.currency.MoneyImpl.money;
+import static org.apidesign.apifest08.test.Task1Test.CZK;
+import static org.apidesign.apifest08.test.Task1Test.SKK;
+import static org.apidesign.apifest08.test.Task1Test.USD;
+import junit.framework.TestCase;
+
+import org.apidesign.apifest08.currency.Convertor;
+import org.apidesign.apifest08.currency.ExtendedConvertor;
+
+/** There are many currencies around the world and many banks manipulate
+ * with more than one or two at the same time. As banks are usually the
+ * best paying clients, which is true even in case of your Convertor API,
+ * it is reasonable to listen to their requests.
+ * <p>
+ * The quest for today is to enhance your existing convertor API to hold
+ * information about many currencies and allow conversions between any of them.
+ * Also, as conversion rates for diferent currencies usually arise from various
+ * bank departments, there is another important need. There is a need to
+ * compose two convertors into one by merging all the information about
+ * currencies they know about.
+ */
+public class Task2Test extends TestCase {
+    public Task2Test(String testName) {
+        super(testName);
+    }
+
+    @Override
+    protected void setUp() throws Exception {
+    }
+
+    @Override
+    protected void tearDown() throws Exception {
+    }
+
+    // As in Task1Test, keep in mind, that there are three parts
+    // of the whole system:
+    // 1. there is someone who knows the current exchange rate
+    // 2. there is someone who wants to do the conversion
+    // 3. there is the API between 1. and 2. which allows them to communicate
+    // 
+    // Please backward compatibly enhance your existing API to support following
+    // usecases:
+    //
+    
+    /** Create convertor that understands two currencies, CZK and
+     *  SKK. Make 100 SKK == 75 CZK. This is method for the group of users that
+     *  knows the exchange rate, and needs to use the API to create objects
+     *  with the exchange rate. Anyone shall be ready to call this method without
+     *  any other method being called previously. The API itself shall know
+     *  nothing about any rates, before this method is called.
+     */
+    public static Convertor createTripleConvertor() {
+        // Rates: 1USD = 15CZK
+        // Rates: 1USD = 20SKK
+        // Rates: 75CZK = 100SKK
+	   return mergeConvertors(
+			   createConvertor(money(1, USD),  money(15, CZK)),
+			   createConvertor(money(1, USD),  money(20, SKK)),
+			   createConvertor(money(75, CZK), money(100, SKK))
+       );
+    }
+
+    /** Define convertor that understands three currencies. Use it.
+     */
+    public void testConvertorForUSDandCZKandSKK() throws Exception {
+        Convertor c = createTripleConvertor();
+
+        // convert $5 to CZK using c:
+        assertEquals("Result is 75 CZK", money(75, CZK),c.convert(money(5,USD), CZK));
+
+        // convert $5 to SKK using c:
+        assertEquals("Result is 100 SKK", money(100, SKK),c.convert(money(5,USD), SKK));
+
+        // convert 200SKK to CZK using c:
+        assertEquals("Result is 150 CZK", money(150, CZK),c.convert(money(200,SKK), CZK));
+
+        // convert 200SKK to USK using c:
+        assertEquals("Result is 10 USD", money(10, USD),c.convert(money(200,SKK), USD));
+    }
+
+    /** Merge all currency rates of convertor 1 with convertor 2.
+     * Implement this using your API, preferably this method just delegates
+     * into some API method which does the actual work, without requiring
+     * API clients to code anything complex.
+     */
+    public static Convertor merge(Convertor one, Convertor two) {
+        return mergeConvertors((ExtendedConvertor)one, (ExtendedConvertor)two);
+    }
+
+    /** Join the convertors from previous task, Task1Test and show that it
+     * can be used to do reasonable conversions.
+     */
+    public void testConvertorComposition() throws Exception {
+        Convertor c = merge(
+            Task1Test.createCZKtoUSD(),
+            Task1Test.createSKKtoCZK()
+        );
+
+        // convert $5 to CZK using c:
+        assertEquals("Result is 85 CZK", money(85, CZK),c.convert(money(5,USD), CZK));
+
+        // convert $8 to CZK using c:
+        assertEquals("Result is 136 CZK", money(136, CZK),c.convert(money(8,USD), CZK));
+
+        // convert 1003CZK to USD using c:
+        assertEquals("Result is 59 USD", money(59, USD),c.convert(money(1003,CZK), USD));
+
+        // convert 16CZK using c:
+        assertEquals("Result is 20 SKK", money(20, SKK),c.convert(money(16,CZK), SKK));
+
+        // convert 500SKK to CZK using c:
+        assertEquals("Result is 400 CZK", money(400, CZK),c.convert(money(500,SKK), CZK));
+
+    }
+}