public EurekaEndpointGroupBuilder secureVipAddress(String secureVipAddress) {
        requireNonNull(secureVipAddress, "secureVipAddress");
        checkArgument(!secureVipAddress.isEmpty(), "secureVipAddress is empty.");
        checkState(appName == null && instanceId == null && vipAddress == null,
                   "cannot set secureVipAddress with the %s.",
                   vipAddress != null ? "vipAddress" : "appName or instanceId");
        this.secureVipAddress = secureVipAddress;
        return this;
    }
Sets the specified {@code secureVipAddress}. {@link EurekaEndpointGroup} will retrieve the
registry information whose VIP address is the specified {@code secureVipAddress}.

@throws IllegalStateException if {@link #appName(String)}, {@link #instanceId(String)} or
                              {@link #vipAddress(String)} is called already
eureka/src/main/java/com/linecorp/armeria/client/eureka/EurekaEndpointGroupBuilder.java