persistence using jsessionid from URI

Hi there, I m looking at some code. I m confused why we add an entry(using persist add uie) for cookies but not for URIs?

https://devcentral.f5.com/codeshare?sid=738

when HTTP_REQUEST {  
     Log details for the request  
    set log_prefix "[IP::client_addr]:[TCP::client_port]"  
    log local0. "$log_prefix: Request to [HTTP::uri] with cookie: [HTTP::cookie value JSESSIONID]
     Check if there is a JSESSIONID cookie  
    if { [HTTP::cookie "JSESSIONID"] ne "" }  {  
         Persist off of the cookie value with a timeout of 1 hour (3600 seconds)  
        persist uie [string tolower [HTTP::cookie "JSESSIONID"]] 3600  
         Log that we're using the cookie value for persistence and the persistence key if it exists.
        log local0. "$log_prefix: Used persistence record from cookie. Existing key? [persist lookup uie [string tolower [HTTP::cookie "JSESSIONID"]]]"  
    } else {  
         Parse the jsessionid from the path. The jsessionid, when included in the URI, is in the path, 
         not the query string: /path/to/file.ext;jsessionid=1234?param=value
        set jsess [findstr [string tolower [HTTP::path]] "jsessionid=" 11]
         Use the jsessionid from the path for persisting with a timeout of 1 hour (3600 seconds)
        if { $jsess != "" } {
            persist uie $jsess 3600
             Log that we're using the path jessionid for persistence and the persistence key if it exists.
            log local0. "$log_prefix: Used persistence record from path: [persist lookup uie $jsess]"
        }
   }
}
when HTTP_RESPONSE {    
    Check if there is a jsessionid cookie in the response
   if { [HTTP::cookie "JSESSIONID"] ne "" }{
        Persist off of the cookie value with a timeout of 1 hour (3600 seconds)
       persist add uie [string tolower [HTTP::cookie "JSESSIONID"]] 3600
       log local0. "$log_prefix: Added persistence record from cookie: [persist lookup uie [string tolower [HTTP::cookie "JSESSIONID"]]]"
   }
}