github.com/MontFerret/ferret@v0.18.0/e2e/tests/dynamic/element/query/element_not_found_by_xpath.fql (about)

     1  LET url = @lab.cdn.dynamic
     2  LET doc = DOCUMENT(url, true)
     3  
     4  LET el = ELEMENT(doc, X("//*[@id='do-not-exist']"))?
     5  
     6  T::NONE(el)
     7  
     8  RETURN TRUE