isActive method
Inquiry method that checks if the Subscription is currently "active" or not.
Most of the Subscription properties cannot be modified if a Subscription
is "active".
The status of a Subscription is changed to "active" through the
LightstreamerClient.subscribe method and back to
"inactive" through the LightstreamerClient.unsubscribe one.
Lifecycle This method can be called at any time.
Returns true/false if the Subscription is "active" or not.
Implementation
bool isActive() {
return _active;
}