code: protected OptionalThing<ExecutedSqlCounter> extractSqlCounter() {
          final CallbackContext context = CallbackContext.getCallbackContextOnThread();
          if (context == null) {
              return OptionalThing.empty();
          }
          final SqlStringFilter filter = context.getSqlStringFilter();
          if (filter == null || !(filter instanceof ExecutedSqlCounter)) {
              return OptionalThing.empty();
          }
          return OptionalThing.of(((ExecutedSqlCounter) filter));
      }
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