old_contents: function test() {
    let x = source();
    
    sink(x); // NOT OK
    
    if (isSafe(x)) {
      sink(x); // OK
    }
  }
  
  class C {
    method() {
      this.x = source();
  
      sink(this.x); // NOT OK
  
      if (isSafe(this.x)) {
        sink(this.x); // OK
  
        addEventListener('hey', () => {
          sink(this.x); // OK - but still flagged
        });
      }
  
      addEventListener('hey', () => {
  	  sink(this.x); // NOT OK
  	});
    }
  }
  
new_contents: function test() {
    let x = source();
    
    sink(x); // NOT OK
    
    if (isSafe(x)) {
      sink(x); // OK
    }
  }
  
  class C {
    method() {
      this.x = source();
  
      sink(this.x); // NOT OK
  
      if (isSafe(this.x)) {
        sink(this.x); // OK
  
        addEventListener('hey', () => {
          sink(this.x); // OK - but still flagged
        });
      }
  
      addEventListener('hey', () => {
  	  sink(this.x); // NOT OK
  	});
  
  	let self = this;
  	if (isSafe(self.x)) {
  	  sink(self.x); // OK
  	}
  
  	addEventListener('hey', function() {
  	  if (isSafe(self.x)) {
  	    sink(self.x); // OK
  	  }
  	});
    }
  }
  
subject: add test with self=this variable