if (source == null) return null;
XBELTerm xt = new XBELTerm();
FunctionEnum functionEnum = source.getFunctionEnum();
Function func = Function.fromValue(functionEnum.getDisplayValue());
xt.setFunction(func);
List<BELObject> functionArgs = source.getFunctionArguments();
List<JAXBElement> prmtrms = xt.getParameterOrTerm();