Huge performance win by getting unit element signature not resolved unit signature
diff --git a/analyzer_plugin/lib/src/angular_driver.dart b/analyzer_plugin/lib/src/angular_driver.dart
index 44d0a05..320d6cf 100644
--- a/analyzer_plugin/lib/src/angular_driver.dart
+++ b/analyzer_plugin/lib/src/angular_driver.dart
@@ -386,7 +386,7 @@
   Future<DirectivesResult> resolveDart(String path,
       {bool withDirectives: false}) async {
     final key =
-        dartDriver.getResolvedUnitKeyByPath(path).toHex() + '.ngresolved';
+        (await dartDriver.getUnitElementSignature(path)) + '.ngresolved';
 
     if (lastSignatures[path] == key) {
       return null;