When the LaunchDarkly client generates analytics events (from flag evaluations, or from the Identify or Track methods), they are queued on a worker thread. The event thread normally sends all queued events to LaunchDarkly at regular intervals, controlled by the EventFlushInterval option. Calling Flush triggers a send without waiting for the next interval.
Flushing is asynchronous, so this method will return before it is complete. However, if you shut down the client with Dispose, events are guaranteed to be sent before that method returns.