java.lang.IllegalArgumentException: partName

	at org.apache.poi.openxml4j.opc.OPCPackage.removePart(OPCPackage.java:1003)
	at org.apache.poi.openxml4j.opc.OPCPackage.removePart(OPCPackage.java:989)
	at org.apache.poi.POIXMLDocumentPart.removeRelation(POIXMLDocumentPart.java:335)
	at org.apache.poi.POIXMLDocumentPart.removeRelation(POIXMLDocumentPart.java:300)
	at org.apache.poi.xslf.usermodel.XSLFSheet.removePictureRelation(XSLFSheet.java:649)
	at org.apache.poi.xslf.usermodel.XSLFSheet.removeShape(XSLFSheet.java:333)