in iep-servergroups/src/main/java/com/netflix/iep/servergroups/Instance.java [100:115]
public Instance merge(Instance other) {
if (!node.equals(other.node)) {
throw new IllegalArgumentException("merging is only supported for the same instance");
}
return builder()
.node(node)
.privateIpAddress(orElse(privateIpAddress, other.privateIpAddress))
.ipv6Address(orElse(ipv6Address, other.ipv6Address))
.vpcId(orElse(vpcId, other.vpcId))
.subnetId(orElse(subnetId, other.subnetId))
.ami(orElse(ami, other.ami))
.vmtype(orElse(vmtype, other.vmtype))
.zone(orElse(zone, other.zone))
.status(status.ordinal() > other.status.ordinal() ? status : other.status)
.build();
}