C#: Add TargetAPI class.

csharp/ql/src/utils/model-generator/ModelGeneratorUtilsSpecific.qll

@@ -0,0 +1,12 @@
+import csharp
+private import semmle.code.csharp.commons.Util
+
+private predicate isRelevantForModels(Callable api) { not api instanceof MainMethod }
+
+class TargetAPI extends Callable {
+  TargetAPI() {
+    [this.(Modifiable), this.(Accessor).getDeclaration()].isEffectivelyPublic() and
+    this.fromSource() and
+    isRelevantForModels(this)
+  }
+}