Warning: individuals_changed is deprecated. Use Folks.IndividualAggregator.individuals_changed_detailed.
Emitted when one or more Individuals are added to or removed from the aggregator.
If more information about the relationships between Individuals which have been linked and unlinked is needed, consider connecting to IndividualAggregator.individuals_changed_detailed instead, which is emitted at the same time as this signal.
This will not be emitted until after IndividualAggregator.prepare has been called.
a list of Individuals which have been added
a list of Individuals which have been removed
a string message from the backend, if any
the Persona who made the change, if known
the reason for the change