public void setVpcIds(java.util.Collection<String> vpcIds) {
        if (vpcIds == null) {
            this.vpcIds = null;
            return;
        }

        this.vpcIds = new java.util.ArrayList<String>(vpcIds);
    }
<p>
The unique identifiers of the VPCs that you want Network Firewall to retrieve the firewalls for. Leave this blank
to retrieve all firewalls that you have defined.
</p>

@param vpcIds
       The unique identifiers of the VPCs that you want Network Firewall to retrieve the firewalls for. Leave
       this blank to retrieve all firewalls that you have defined.
aws-java-sdk-networkfirewall/src/main/java/com/amazonaws/services/networkfirewall/model/ListFirewallsRequest.java