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

        this.groups = new com.amazonaws.internal.SdkInternalList<String>(groups);
    }
<p>
The IDs of the security groups. You cannot specify security groups from a different VPC.
</p>

@param groups
       The IDs of the security groups. You cannot specify security groups from a different VPC.
aws-java-sdk-ec2/src/main/java/com/amazonaws/services/ec2/model/AttachClassicLinkVpcRequest.java