How to detect selenium / webdriver on my site

Question

Does anyone know how to detect selenium / webdriver on my site?

I do not want to block them, I just discover them.

I saw this question: Can a site be detected when using selenium with chrome ribs?

But trying all of them in the latest version does not work.

Does any body know anything else?

PS please do not leave answers / comments "do not block" / "you are looking in the wrong place" - I am fully aware of what I ask and what will be the business logic for using it.

- EDIT -

Things I tested from the link above:

• detection of the cdc_asdjflasutopfhvcZLmcfl_ key on the elements, mainly on the window and the document, but some other elements that we have on the entire site.

• The search window.navigator.webdriveralways returns undefinedinstead true(checked on both chrome and firefox, although only firefox supports it)

• checked the script for this answer: stack overflow

All tests were performed using the latest seleniums, browsers (firefox and chrome) and the latest webdriver plugins. so far only on windows, but will probably also check ubuntu.