Host header based web farm iRule & Class

I updated the rule to not error if the class did not exist:

rule RULE_POOLMAPPING_V01 {
    when RULE_INIT {
        set static::CLASS "CLASS_POOLMAPPING_V01"
        set static::DEBUG 0
        set static::HTTPS_PORT 443
    }
    when HTTP_REQUEST {
        if { [class exists $static::CLASS] } {
            set zone_pool [class match -element -- [string tolower [HTTP::host]] equals $static::CLASS]
        }
        if { [info exists zone_pool] && [llength $zone_pool] == 2 } {
            set pool [lindex $zone_pool 1]
            if { [TCP::local_port clientside] equals $static::HTTPS_PORT } {
                append pool "S"
            }
            if { $static::DEBUG } {
                log local0. "WEBCLUSTER DEBUG: [HTTP::host]->$pool"
            }
            if { [catch { pool $pool }] } {
                log local0. "WEBCLUSTER ERROR: Non-existant pool: $pool"
            }
        } elseif { $static::DEBUG } {
            log local0. "WEBCLUSTER DEBUG: No match for host: [HTTP::host]"
        }
    }
}