killbill-memoizeit

diff --git a/api/src/main/java/com/ning/billing/invoice/api/InvoiceUserApi.java b/api/src/main/java/com/ning/billing/invoice/api/InvoiceUserApi.java
index 38543f2..91b0917 100644
--- a/api/src/main/java/com/ning/billing/invoice/api/InvoiceUserApi.java
+++ b/api/src/main/java/com/ning/billing/invoice/api/InvoiceUserApi.java
@@ -22,8 +22,6 @@ import java.util.Collection;
 import java.util.List;
 import java.util.UUID;
 
-import javax.annotation.Nullable;
-
 import org.joda.time.LocalDate;
 
 import com.ning.billing.account.api.AccountApiException;
@@ -160,20 +158,33 @@ public interface InvoiceUserApi {
                                               Currency currency, CallContext context) throws InvoiceApiException;
 
     /**
-     * Adjust a given invoice item.
+     * Adjust fully a given invoice item.
+     *
+     * @param accountId     account id
+     * @param invoiceId     invoice id
+     * @param invoiceItemId invoice item id
+     * @param effectiveDate the effective date for this adjustment invoice item
+     * @param context       the call context
+     * @return the adjustment invoice item
+     * @throws InvoiceApiException
+     */
+    public InvoiceItem insertInvoiceItemAdjustment(UUID accountId, UUID invoiceId, UUID invoiceItemId, LocalDate effectiveDate, CallContext context) throws InvoiceApiException;
+
+    /**
+     * Adjust partially a given invoice item.
      *
      * @param accountId     account id
      * @param invoiceId     invoice id
      * @param invoiceItemId invoice item id
      * @param effectiveDate the effective date for this adjustment invoice item
-     * @param amount        the adjustment amount. Pass null to adjust for the full amount of the original item
-     * @param currency      adjustment currency. Pass null to use the original currency
+     * @param amount        the adjustment amount
+     * @param currency      adjustment currency
      * @param context       the call context
      * @return the adjustment invoice item
      * @throws InvoiceApiException
      */
     public InvoiceItem insertInvoiceItemAdjustment(UUID accountId, UUID invoiceId, UUID invoiceItemId, LocalDate effectiveDate,
-                                                   @Nullable BigDecimal amount, @Nullable Currency currency, CallContext context) throws InvoiceApiException;
+                                                   BigDecimal amount, Currency currency, CallContext context) throws InvoiceApiException;
 
     /**
      * Retrieve the invoice formatted in HTML.

diff --git a/invoice/src/main/java/com/ning/billing/invoice/api/user/DefaultInvoiceUserApi.java b/invoice/src/main/java/com/ning/billing/invoice/api/user/DefaultInvoiceUserApi.java
index 2fc3623..927db0b 100644
--- a/invoice/src/main/java/com/ning/billing/invoice/api/user/DefaultInvoiceUserApi.java
+++ b/invoice/src/main/java/com/ning/billing/invoice/api/user/DefaultInvoiceUserApi.java
@@ -158,6 +158,11 @@ public class DefaultInvoiceUserApi implements InvoiceUserApi {
     }
 
     @Override
+    public InvoiceItem insertInvoiceItemAdjustment(final UUID accountId, final UUID invoiceId, final UUID invoiceItemId, final LocalDate effectiveDate, final CallContext context) throws InvoiceApiException {
+        return insertInvoiceItemAdjustment(accountId, invoiceId, invoiceItemId, effectiveDate, null, null, context);
+    }
+
+    @Override
     public InvoiceItem insertInvoiceItemAdjustment(final UUID accountId, final UUID invoiceId, final UUID invoiceItemId,
                                                    final LocalDate effectiveDate, @Nullable final BigDecimal amount,
                                                    @Nullable final Currency currency, final CallContext context) throws InvoiceApiException {

diff --git a/invoice/src/test/java/com/ning/billing/invoice/api/user/TestDefaultInvoiceUserApi.java b/invoice/src/test/java/com/ning/billing/invoice/api/user/TestDefaultInvoiceUserApi.java
index 88ce414..2de15d7 100644
--- a/invoice/src/test/java/com/ning/billing/invoice/api/user/TestDefaultInvoiceUserApi.java
+++ b/invoice/src/test/java/com/ning/billing/invoice/api/user/TestDefaultInvoiceUserApi.java
@@ -136,7 +136,7 @@ public class TestDefaultInvoiceUserApi extends InvoiceApiTestBase {
 
         // Adjust the invoice for the full amount
         final InvoiceItem adjInvoiceItem = invoiceUserApi.insertInvoiceItemAdjustment(accountId, invoiceId, invoiceItem.getId(),
-                                                                                      clock.getUTCToday(), null, null, context);
+                                                                                      clock.getUTCToday(), context);
         Assert.assertEquals(adjInvoiceItem.getInvoiceId(), invoiceId);
         Assert.assertEquals(adjInvoiceItem.getInvoiceItemType(), InvoiceItemType.ITEM_ADJ);
         Assert.assertEquals(adjInvoiceItem.getAccountId(), accountId);