isActive method
Checks if the MpnSubscription is currently "active" or not.
Most of the MpnSubscription properties cannot be modified if an MpnSubscription is "active".
The status of an MpnSubscription is changed to "active" through the LightstreamerClient.subscribe method and back to "inactive"
through the LightstreamerClient.unsubscribe and LightstreamerClient.unsubscribeMpnSubscriptions ones.
Lifecycle This method can be called at any time.
Returns true if the MpnSubscription is currently "active", false otherwise.
Implementation
external bool isActive();