Whitelist certain inbound IPs

Could someone verify if this syntax is correct, please? 

I am looking to only permit certain source IPs contained in the data group "abc_ips" when navigating to a URL and dropping anything else. 

when HTTP_REQUEST {
	if { [class match [IP::client_addr] eq "abc_ips" ] } { 
		return
	} else {
		drop
	}
  }