JAVAMONEY-83: Changed context key type from Object to String, removed methods containing defaults.

Author: atsticks

src/main/java/org/javamoney/moneta/spi/LazyBoundCurrencyConversion.java

@@ -51,6 +51,11 @@ public ExchangeRate getExchangeRate(MonetaryAmount amount) {
         return this.rateProvider.getExchangeRate(amount.getCurrency(), getCurrency());
     }
 
+    @Override
+    public ExchangeRateProvider getExchangeRateProvider() {
+        return this.rateProvider;
+    }
+
     /*
      * (non-Javadoc)
      *

src/test/java/org/javamoney/moneta/function/CurrencyConversionMock.java

@@ -11,6 +11,7 @@
 import javax.money.convert.ConversionContext;
 import javax.money.convert.CurrencyConversion;
 import javax.money.convert.ExchangeRate;
+import javax.money.convert.ExchangeRateProvider;
 
 import org.javamoney.moneta.Money;
 
@@ -58,6 +59,11 @@ public ExchangeRate getExchangeRate(MonetaryAmount sourceAmount) {
         return null;
     }
 
+    @Override
+    public ExchangeRateProvider getExchangeRateProvider() {
+        return null;
+    }
+
     private class DollarConversation implements Conversation {
         private CurrencyUnit currency = DOLLAR;