Iterator<FieldMap> iter = fields.iterator();
while(iter.hasNext()) {
FieldMap fieldMap = iter.next();
if (!fieldMap.is(aMappingOfTheRequiredClassProperty())) {
if ( !aToB) {
fieldMap = fieldMap.flip();
}
if (fieldMap.getSource().getName().equals(arg)) {
targetParameters.put(arg, fieldMap);
iter.remove();
}