Fires an event when the composition starts.
Typically you would want just one of these nodes in a composition. Multiple
Fire on Start nodes fire separate events and are not synchronized with each other.
There is no guarantee that this node will be the first to fire within a composition. For example, a rapidly firing Fire Periodically node may fire first.
An alternative to this node that’s more suitable for protocol compositions, since it doesn’t fire an event, is Allow First Event.
Keywords: bang, begin, events, fire, first, init, launch, main, pulse, signal, trigger