public class PartitionBridgeHandler extends BaseBridgeHandler {

...
  private void receiveUpdateFromSource(int sourceID) {
    PartitionBridgeConfiguration config;
    for (Thing eachThing:  this.getBridge().getThings()) {
        config =  eachThing.getConfiguration().as(PartitionBridgeConfiguration.class);
        if (config.sourceID == sourceID) {
             // Found the thing
            eachThing.getHandler().updateState(...);
        } else {
            // not found suggest add to discovery... but how?
       }        
    }
  }
...  

}