code: public void setReferral(int referral) {
  	if (referral > 0) {
  	    env.put("java.naming.referral", "follow");
  	    env.put("java.naming.ldap.referral.limit", Caster.toString(referral));
  	}
  	else {
  	    env.put("java.naming.referral", "ignore");
  	    env.remove("java.naming.ldap.referral.limit");
  	}
      }
docs: sets thr referral
  
  @param referral