Problem this snippet solves: TMOS v12.1.4.1 and v13 have a change where the output of X509::subject is formatted to match OpenSSL output. See https://cdn.f5.com/product/bugtracker/ID607410.html ...
uniqng this splits the DN on the comma so if there is an unexpected comma then it will break. If you have complex, specific requirements then I suggest you decode the field using the ASN1 commands