I'm translating SAP Idoc to ANSI X12. My input file is an idoc with a series of segments identified as E1EDP16. I need to call a functional map on just the last E1EDP16 segment. So if given an idoc with 6 E1EDP16 segments, I don't want the functional map to be called until the 6th E1EDP16 segment. Any ideas how to do this?