diff -r 000000000000 -r 80f2d8751f35 task2/solution12/test/org/apidesign/apifest08/test/Task2Test.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/task2/solution12/test/org/apidesign/apifest08/test/Task2Test.java	Tue Oct 07 00:17:07 2008 +0200
@@ -0,0 +1,132 @@
+package org.apidesign.apifest08.test;
+
+import java.util.Currency;
+
+import junit.framework.TestCase;
+
+import org.apidesign.apifest08.currency.Convertor;
+import org.apidesign.apifest08.currency.exceptions.UnknownConvertorException;
+
+/** 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
+    	// set exchange rates
+    	Convertor.setConvertorRates(Currency.getInstance("USD"), Currency.getInstance("CZK"), 15, 1);
+    	Convertor.setConvertorRates(Currency.getInstance("USD"), Currency.getInstance("SKK"), 20, 1);
+    	Convertor.setConvertorRates(Currency.getInstance("SKK"), Currency.getInstance("CZK"), 75, 100);
+        
+        // create new instance
+        Convertor convertor = null;
+        try {
+          convertor = Convertor.getConvertorInstance(Currency.getInstance("USD"), Currency.getInstance("SKK"), Currency.getInstance("CZK"));
+        } catch (UnknownConvertorException e) {
+          e.printStackTrace();
+        }
+    	return convertor;
+    }
+
+    /** Define convertor that understands three currencies. Use it.
+     */
+    public void testConvertorForUSDandCZKandSKK() throws Exception {
+        Convertor c = createTripleConvertor();
+
+        // convert $5 to CZK using c:
+        double result = c.convert(5d, Currency.getInstance("USD"), Currency.getInstance("CZK"));
+        assertEquals("Result is not 75 CZK", 75.0, result);
+
+        // convert $5 to SKK using c:
+        result = c.convert(5d, Currency.getInstance("USD"), Currency.getInstance("SKK"));
+        assertEquals("Result is not 100 SKK", 100.0, result);
+
+        // convert 200SKK to CZK using c:
+        result = c.convert(200d, Currency.getInstance("SKK"), Currency.getInstance("CZK"));
+        assertEquals("Result is not 150 CZK", 150.0, result);
+
+        // convert 200SKK to USK using c:
+        result = c.convert(200d, Currency.getInstance("SKK"), Currency.getInstance("USD"));
+        assertEquals("Result is not 10 USD", 10.0, result);
+    }
+
+    /** 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 one.merge(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:
+        double result = c.convert(5d, Currency.getInstance("USD"), Currency.getInstance("CZK"));
+        assertEquals("Result is not 85 CZK", 85.0, result);
+
+        // convert $8 to CZK using c:
+        result = c.convert(8d, Currency.getInstance("USD"), Currency.getInstance("CZK"));
+        assertEquals("Result is not 136 CZK", 136.0, result);
+
+        // convert 1003CZK to USD using c:
+        result = c.convert(1003d, Currency.getInstance("CZK"), Currency.getInstance("USD"));
+        assertEquals("Result is not 59 USD", 59.0, result);
+
+        // convert 16CZK using c:
+        result = c.convert(16d, Currency.getInstance("CZK"), Currency.getInstance("SKK"));
+        assertEquals("Result is not 20 SKK", 20.0, result);
+
+        // convert 500SKK to CZK using c:
+        result = c.convert(500d, Currency.getInstance("SKK"), Currency.getInstance("CZK"));
+        assertEquals("Result is not 400 CZK", 400.0, result);
+
+    }
+}