@Override
    public CompletableFuture<List<Endpoint>> whenReady() {
        return initialEndpointsFuture;
    }
Creates a {@link XdsEndpointGroup} based on the specified {@link ClusterSnapshot}.
This may be useful if one would like to create an {@link EndpointGroup} based on
a {@link GrpcService}.
xds/src/main/java/com/linecorp/armeria/xds/client/endpoint/XdsEndpointGroup.java