code: protected CheckSchemaOperation createCheckSchemaOperation() {
          InputStream in =
              AbstractBundlePersistenceManager.class.getResourceAsStream(
                      databaseType + ".ddl");
          return new CheckSchemaOperation(conHelper, in, schemaObjectPrefix + "BUNDLE").addVariableReplacement(
              CheckSchemaOperation.SCHEMA_OBJECT_PREFIX_VARIABLE, schemaObjectPrefix);
      }
docs: This method is called from {@link #init(PMContext)} after the
  {@link #createConnectionHelper(DataSource)} method, and returns a default {@link CheckSchemaOperation}.
  Subclasses can overrride this implementation to get a customized implementation.
  
  @return a new {@link CheckSchemaOperation} instance