diff -r a3144e7f9c90 -r 58ec6da75f6f task4/solution02/test/org/apidesign/apifest08/test/OnlineConvertor.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/task4/solution02/test/org/apidesign/apifest08/test/OnlineConvertor.java	Sat Oct 11 23:38:46 2008 +0200
@@ -0,0 +1,54 @@
+package org.apidesign.apifest08.test;
+
+import java.math.BigDecimal;
+import java.util.Currency;
+
+import org.apidesign.apifest08.currency.ConvertorFactory;
+import org.apidesign.apifest08.currency.ExtendedConvertor;
+import org.apidesign.apifest08.currency.Money;
+import org.apidesign.apifest08.currency.MoneyImpl;
+
+/**
+ * Third party implementation of the convertor. IT IS NOT THREAD SAFE.
+ * @author lukas
+ *
+ */
+class OnlineConvertor implements ExtendedConvertor {
+	
+	private static final BigDecimal LOWER_LIMIT = BigDecimal.valueOf(15);
+	private static final BigDecimal HIGHER_LIMIT = BigDecimal.valueOf(16);
+	
+	private static final Currency USD = Currency.getInstance("USD");
+	private static final Currency CZK = Currency.getInstance("CZK");
+	private static final MoneyImpl ONE_USD = new MoneyImpl(1,USD);
+	
+	private ExtendedConvertor wrappedConvertor = ConvertorFactory.createConvertor(ONE_USD, new MoneyImpl(16, CZK));
+	
+	private BigDecimal increment = new BigDecimal("-0.01");
+	
+	public boolean isConversionSupported(Currency from, Currency to) {
+		return wrappedConvertor.isConversionSupported(from, to);
+	}
+
+	public Money convert(Money amount, Currency destinationCurrency)
+			throws IllegalArgumentException {
+		Money result = wrappedConvertor.convert(amount, destinationCurrency);
+		updateConvertor();
+		return result;
+	}
+
+	/**
+	 * Prepares convertor for the next conversion.
+	 */
+	private void updateConvertor() {
+		BigDecimal currentRate = wrappedConvertor.convert(ONE_USD, CZK).getAmount();
+		BigDecimal newRate = currentRate.add(increment);
+		
+		if (LOWER_LIMIT.compareTo(newRate)==0 || HIGHER_LIMIT.compareTo(newRate)==0)
+		{
+			increment = increment.negate();
+		}
+		wrappedConvertor = ConvertorFactory.createConvertor(ONE_USD, new MoneyImpl(newRate, CZK));
+	}
+
+}