code: String getDatabaseName(String dbName) {
          if (mFileNameMap == null) {
              return null;
          }
          String name = mFileNameMap.get(dbName);
          if (name == null && dbName != null) {
              name = mFileNameMap.get(null);
          }
          if (name == null) {
              return null;
          }
          if (mDatabaseHook != null) {
              try {
                  dbName = mDatabaseHook.databaseName(dbName);
              } catch (IncompatibleClassChangeError e) {
                  // Method not implemented.
              }
          }
          return dbName;
      }
docs: Returns null if name should not be used.