Add AbstractDynamoDbStore#scan

service/src/main/java/org/whispersystems/textsecuregcm/storage/AbstractDynamoDbStore.java

@@ -68,6 +68,15 @@ public class AbstractDynamoDbStore {
     }
   }
 
+  protected List<Map<String, AttributeValue>> scan(ScanRequest scanRequest, int max) {
+
+    return db().scanPaginator(scanRequest)
+        .items()
+        .stream()
+        .limit(max)
+        .collect(Collectors.toList());
+  }
+
   static <T> void writeInBatches(final Iterable<T> items, final Consumer<List<T>> action) {
     final List<T> batch = new ArrayList<>(DYNAMO_DB_MAX_BATCH_SIZE);