How to specify in a check_plugins data as a counter

Hi

In the doc Writing your own check plug-ins is written:
“The auxiliary functions for working with counters, rates and averages have changed.”

But I can’t find a documentation that explains how I can specify in a plugin if data is a counter or a normal value?

Are there any examples or documentation about this?

Thanks, Manuel

Look at the check API documentation available through the Help menu of your site. The method is get_rate().