c# - Resharper ContractAnnotation for null-check not eliminating NRE warning -

i'm having problem extension method, annotated contractannotation tell r# null-ness of object doesn't result in nre warning going away. here's how projects laid out:

project1: jetbrainsextensions has r# annotations class defines contractannotation

project2: mybaselibrary references project1 , has extension method this:

[contractannotation("null => true; notnull => false")] public static bool isnull(this object aobject) {     return referenceequals(null, aobject); } 

project3: mybusinesslogic using mybaselibrary project , wants this:

if (myvariable.isnull())      return;  myvariable.dostuff(); 

the line: myvariable.dostuff(); warning there's possible null reference exception.

i've followed advice listed in many/all of related stackoverflow posts regarding how annotation should written. i've tried:

[contractannotation("aobject:null => true; aobject:notnull => false")] 

and

[contractannotation("aobject:null => true")] 

i've tried:

if (myvariable.isnull())     return;  else     myvariable.dosomething(); 

thinking if/else construct save it. no dice.

i'm suspecting issue multi-project/assembly way i'm packaging it, i'm not entirely sure. idea do?

---

update: i'm using reshaper 8.2. i've tried putting r# annotation inside businesslogic project , i've put new extension method inside project well. neither of have worked remove nre.