code: @Implementation
    protected int update(Uri uri, ContentValues values, String where, String[] selectionArgs) {
      ContentProvider provider = getProvider(uri);
      ContentValues valuesCopy = (values == null) ? null : new ContentValues(values);
      UpdateStatement updateStatement =
          new UpdateStatement(uri, provider, valuesCopy, where, selectionArgs);
      statements.add(updateStatement);
      updateStatements.add(updateStatement);
  
      if (provider != null) {
        return provider.update(uri, values, where, selectionArgs);
      } else {
        return 1;
      }
    }
docs: If a {@link ContentProvider} is registered for the given {@link Uri}, its
  {@link ContentProvider#update(Uri, ContentValues, String, String[])} method will be invoked.
  
  Tests can verify that this method was called using {@link #getStatements()} or
  {@link #getUpdateStatements()}.
  
  @return If no appropriate {@link ContentProvider} is found, no action will be taken and 1 will
  be returned.