Restrict fluent api models to same type access

java/ql/src/utils/model-generator/CaptureSummaryModels.ql

@@ -22,7 +22,7 @@ string captureFlow(Callable api) {
 string captureQualifierFlow(Callable api) {
   exists(ReturnStmt rtn |
     rtn.getEnclosingCallable() = api and
-    rtn.getResult() instanceof ThisAccess
+    rtn.getResult().(ThisAccess).isOwnInstanceAccess()
   ) and
   result = asValueModel(api, "Argument[-1]", "ReturnValue")
 }

java/ql/test/utils/model-generator/p/FluentAPI.java

@@ -6,4 +6,10 @@ public final class FluentAPI {
         return this;
     }
 
+    public class Inner {
+        public FluentAPI notThis(String input) {
+            return FluentAPI.this;
+        }
+    }
+
 }