code: Integer getDatabasePageSize(Class<? extends Storable> type) {
          if (mDatabasePageSizes == null) {
              return null;
          }
          Integer size = mDatabasePageSizes.get(type);
          if (size == null && type != null) {
              size = mDatabasePageSizes.get(null);
          }
          return size;
      }
docs: Returns the desired page size for the given type, or null for default.