anchor.diff:      return x + 1;
   };
   var x1 = 2;
  +__PS_MV_REG = [];
   return x(x1);
   })();")
   
  
positive.code:             foo(y);
          };
      } else {
          return c;
      };
  };")
  
negative.code:               (1+ a))))
    "x = (function () {
      var a = foo();
      __PS_MV_REG = [];
      return a != null ? a + 1 : null;
  })();")
  
  