// For each check export identify the variable used
for (CheckExport export : check.getExports()) {
String variableId = export.getName();
if (retval.containsKey(variableId)) {
// Looks like a duplicate variable export
CheckExport value = retval.get(variableId);
// if the exports are not the same
if (!export.equals(value)) {
throw new RuntimeException("the same variable '"+variableId+"' is being exported multiple times");
}
} else {