diff -r 000000000000 -r 2ae6e4aa7aef taskx/psmid/against-solution04/test/apifest/CurrencyTest.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/taskx/psmid/against-solution04/test/apifest/CurrencyTest.java	Sat Oct 25 20:53:00 2008 +0200
@@ -0,0 +1,42 @@
+package apifest;
+
+import java.math.BigDecimal;
+import java.util.Currency;
+import junit.framework.TestCase;
+import org.apidesign.apifest08.currency.Convertor;
+import org.apidesign.apifest08.currency.ConvertorFactory;
+import org.apidesign.apifest08.currency.InvalidConversionException;
+
+
+/** Write a test that works with version from task A and fails with version B.
+ */
+public class CurrencyTest extends TestCase {
+    public CurrencyTest(String n) {
+        super(n);
+    }
+    
+    public void testCompatibility() throws Exception {
+        incompatibility1();
+      //  incompatibility2(); //another test proving incompatibility in versions
+      //  incompatibility3(); //another test proving incompatibility in versions
+    }
+
+    private void incompatibility1() throws Exception {
+          Convertor c = ConvertorFactory.getConvertor("CZK", BigDecimal.valueOf(17.0), "USD", BigDecimal.valueOf(1));
+          assertTrue("", c.toString().startsWith("org.apidesign.apifest08.currency.ConvertorImpl"));
+    }
+
+    private void incompatibility2() throws Exception {
+          Convertor c = ConvertorFactory.getConvertor("CZK", BigDecimal.valueOf(17.0), "USD", BigDecimal.valueOf(1));
+          assertEquals("Testing hashcode", 961187025, c.hashCode());
+    }
+
+    private void incompatibility3() throws Exception {
+        Convertor co = new Convertor() {
+            public BigDecimal convert(Currency from, Currency to, BigDecimal amount) throws InvalidConversionException {
+                return null;
+            }
+        };
+    }
+
+}