public void setRules(String rules) {
        this.rules = rules;
    }
<p>
A string containing stateful rule group rules specifications in Suricata flat format, with one rule per line. Use
this to import your existing Suricata compatible rule groups.
</p>
<note>
<p>
You must provide either this rules setting or a populated <code>RuleGroup</code> setting, but not both.
</p>
</note>
<p>
You can provide your rule group specification in Suricata flat format through this setting when you create or
update your rule group. The call response returns a <a>RuleGroup</a> object that Network Firewall has populated
from your string.
</p>

@param rules
       A string containing stateful rule group rules specifications in Suricata flat format, with one rule per
       line. Use this to import your existing Suricata compatible rule groups. </p> <note>
       <p>
       You must provide either this rules setting or a populated <code>RuleGroup</code> setting, but not both.
       </p>
       </note>
       <p>
       You can provide your rule group specification in Suricata flat format through this setting when you create
       or update your rule group. The call response returns a <a>RuleGroup</a> object that Network Firewall has
       populated from your string.
aws-java-sdk-networkfirewall/src/main/java/com/amazonaws/services/networkfirewall/model/UpdateRuleGroupRequest.java