public EndpointIdentity[] GetEndpointsIdentities(string monitorTag = null)
{
Func<Endpoint, bool> predicate = e => true;
if (monitorTag != null)
predicate = e => string.Equals(e.Metadata.MonitorTag, monitorTag, StringComparison.OrdinalIgnoreCase);
return _endpointRegistry.Endpoints.Where(predicate).Select(e => e.Identity).ToArray();
}