altered pdf file is still validated

[rachmanmarjianto]

I tried to validate an altered PDF and the validation's result is still true. Then I checked your validation code.
This line gives the validation result --> isValidated : true
$finalContent['validated'] = !!count(array_intersect_key(array_flip(['OU', 'CN']), $finalContent));

I don't understand, what does the variable isValidated in ValidatedSignedPDF's object mean?