final Collection<ExpressionProxy> proxys = _invarients.values();
if(!proxys.isEmpty()) {
for(ExpressionProxy proxy : proxys) {
final XQExpression orig = proxy.getOriginalExpr();
final LetVariable lv = new LoopInvariantLetVariable(orig);
proxy.setReplacedExpr(lv);
final LetClause lc = new LetClause(lv);
clauses.add(insertionPoint, lc);
}
_invarients.clear();