killbill-memoizeit

diff --git a/invoice/src/main/java/org/killbill/billing/invoice/usage/ContiguousIntervalUsageInArrear.java b/invoice/src/main/java/org/killbill/billing/invoice/usage/ContiguousIntervalUsageInArrear.java
index 8897c05..08cd36d 100644
--- a/invoice/src/main/java/org/killbill/billing/invoice/usage/ContiguousIntervalUsageInArrear.java
+++ b/invoice/src/main/java/org/killbill/billing/invoice/usage/ContiguousIntervalUsageInArrear.java
@@ -216,8 +216,8 @@ public abstract class ContiguousIntervalUsageInArrear {
                 populateResults(ru.getStart(), ru.getEnd(), billedItems, billedUsage, toBeBilledUsage, toBeBilledUsageDetails, areAllBilledItemsWithDetails, result);
             }
         }
-        final LocalDate nextNotificationdate = computeNextNotificationDate();
-        return new UsageInArrearItemsAndNextNotificationDate(result, nextNotificationdate);
+        final LocalDate nextNotificationDate = computeNextNotificationDate();
+        return new UsageInArrearItemsAndNextNotificationDate(result, nextNotificationDate);
     }
 
     protected abstract void populateResults(final LocalDate startDate, final LocalDate endDate, final Iterable<InvoiceItem> billedItems, final BigDecimal billedUsage, final BigDecimal toBeBilledUsage, final UsageInArrearDetail toBeBilledUsageDetails, final boolean areAllBilledItemsWithDetails, final List<InvoiceItem> result);
@@ -464,18 +464,6 @@ public abstract class ContiguousIntervalUsageInArrear {
         }
     }
 
-    public BigDecimal toBeBilledForUnit(final List<UsageConsumableInArrearTierUnitDetail> toBeBilledDetails, final UsageType usageType) {
-        if (usageType == UsageType.CAPACITY) {
-            return toBeBilledDetails.get(0).getAmount();
-        } else {
-            BigDecimal result = BigDecimal.ZERO;
-            for (UsageConsumableInArrearTierUnitDetail toBeBilled : toBeBilledDetails) {
-                result = result.add(toBeBilled.getAmount());
-            }
-            return result;
-        }
-    }
-
     protected String toJson(final UsageInArrearDetail usageInArrearDetail) {
         try {
             return objectMapper.writeValueAsString(usageInArrearDetail);

diff --git a/invoice/src/test/java/org/killbill/billing/invoice/usage/TestContiguousIntervalConsumableInArrear.java b/invoice/src/test/java/org/killbill/billing/invoice/usage/TestContiguousIntervalConsumableInArrear.java
index 6e0acab..c7ebfa4 100644
--- a/invoice/src/test/java/org/killbill/billing/invoice/usage/TestContiguousIntervalConsumableInArrear.java
+++ b/invoice/src/test/java/org/killbill/billing/invoice/usage/TestContiguousIntervalConsumableInArrear.java
@@ -450,7 +450,7 @@ public class TestContiguousIntervalConsumableInArrear extends TestUsageInArrearB
     }
 
     @Test(groups = "fast")
-    public void testTobeBilledForUnit() throws CatalogApiException {
+    public void testBilledUsage() throws CatalogApiException {
 
         final DefaultTieredBlock block1 = createDefaultTieredBlock("cell-phone-minutes", 1000, 10000, new BigDecimal("0.5"));
         final DefaultTieredBlock block2 = createDefaultTieredBlock("Mbytes", 512, 512000, new BigDecimal("0.3"));
@@ -463,12 +463,14 @@ public class TestContiguousIntervalConsumableInArrear extends TestUsageInArrearB
                                                                                                                                              BillingPeriod.MONTHLY,
                                                                                                                                              Collections.<Usage>emptyList())
                                                                                                                      );
-        List<UsageConsumableInArrearTierUnitDetail> results = Lists.newArrayList();
-        results.addAll(intervalConsumableInArrear.computeToBeBilledConsumableInArrear(new DefaultRolledUpUnit("cell-phone-minutes", 1000L), ImmutableList.<UsageConsumableInArrearTierUnitDetail>of(), true));
-        results.addAll(intervalConsumableInArrear.computeToBeBilledConsumableInArrear(new DefaultRolledUpUnit("Mbytes", 30720L), ImmutableList.<UsageConsumableInArrearTierUnitDetail>of(), true));
-        assertEquals(results.size(), 2);
+        final List<UsageConsumableInArrearTierUnitDetail> tierUnitDetails = Lists.newArrayList();
+        tierUnitDetails.addAll(intervalConsumableInArrear.computeToBeBilledConsumableInArrear(new DefaultRolledUpUnit("cell-phone-minutes", 1000L), ImmutableList.<UsageConsumableInArrearTierUnitDetail>of(), true));
+        tierUnitDetails.addAll(intervalConsumableInArrear.computeToBeBilledConsumableInArrear(new DefaultRolledUpUnit("Mbytes", 30720L), ImmutableList.<UsageConsumableInArrearTierUnitDetail>of(), true));
+        assertEquals(tierUnitDetails.size(), 2);
 
-        assertEquals(intervalConsumableInArrear.toBeBilledForUnit(results, UsageType.CONSUMABLE), new BigDecimal("18.5"));
+        final UsageConsumableInArrearDetail details = new UsageConsumableInArrearDetail(tierUnitDetails);
+
+        assertEquals(details.getAmount().compareTo(new BigDecimal("18.5")), 0);
     }
 
     @Test(groups = "fast")