There could be a default True option to attempt to join a new GTFS feed to an existing GTFS feed. A threshold for how far away the nearest node could be needs to also be implemented. Not all stops should be joined to the existing graph (if it is provided). Any points beyond this threshold should remain in isolation. This can result in the graph being disconnected / weak (although a single GTFS does not itself guarantee a strongly connected graph).
There could be a default
Trueoption to attempt to join a new GTFS feed to an existing GTFS feed. A threshold for how far away the nearest node could be needs to also be implemented. Not all stops should be joined to the existing graph (if it is provided). Any points beyond this threshold should remain in isolation. This can result in the graph being disconnected / weak (although a single GTFS does not itself guarantee a strongly connected graph).