question: public Id < DgCrossingNode > convertNodeId2NotExpandedCrossingNodeId ( Id < Node > nodeId ) { String idString = nodeId . toString ( ) ; return idPool . createId ( idString , DgCrossingNode . class ) ; }
target:  converts a matsim node ID of a node outside the signals bounding box  to the single crossing node ID existing for the not expanded crossing in the ks-model. (the signals bounding box determines the region of spatial expansion: all nodes within this area will be expanded.)