If an error appears inside any of the the Client.group goroutines,
the failed goroutine returns a non-nil error and the whole
Client.group is cancelled using Client.groupCtx. I.e. this condition
is signalized by closed Client.groupCtx.Done() channel.
The Client's API functions should get the error using
Client.group.Wait() call and return it to the caller.
There's no point in returning context.Canceled because
Client.group.Wait() must eventually return in such condition.
If an error appears inside any of the the
Client.groupgoroutines, the failed goroutine returns a non-nilerrorand the wholeClient.groupis cancelled usingClient.groupCtx. I.e. this condition is signalized by closedClient.groupCtx.Done()channel.The
Client's API functions should get the error usingClient.group.Wait()call and return it to the caller. There's no point in returningcontext.CanceledbecauseClient.group.Wait()must eventually return in such condition.