Prometheus.NetCore Monitors all DiagnosticSource events and exposes them as Prometheus counters. The event data is discarded, only the number of occurrences is measured. This is a very coarse data set due to lacking any intelligence on the payload. Users are recommended to make custom adapters with more detail for specific use cases. Starts listening for DiagnosticSource events and reporting them as Prometheus metrics. Dispose of the return value to stop listening. Starts listening for DiagnosticSource events and reporting them as Prometheus metrics. Dispose of the return value to stop listening. By default we subscribe to all listeners but this allows you to filter by listener.