The functions to add/modify events/inputs use named vectors or lists. Whenever several inputs/events are added or modified,
it's recommended to group them within one function, as it reduces the computation cost.
So rather than use two new_event with a list of one element, it's better to group them into a single new_event with a list of two elements.
While multiple events can be added, they must be named differently. If the same event is added multiple times at once, only the last occurrence will be kept
(only one event per event type in the queue of events yet to occur). If an event occurs, then a new one with the same name can be set.
This function is intended to be used only within the add_reactevt function in its input parameter and should not be run elsewhere or it will return an error.