Java – should I always use generics?

I created a unit test:

new Callable() {
@Override
public Object call() throws
         .....

I received a warning in Eclipse:

Callable is a raw type. References to generic type Callable<V> 
should be parameterized

I should write the following code:

new Callable<Object>()

Eliminate warnings, or not? It seems that there is only JUnit test, which makes no sense to add additional code... Thank you

Solution

If your operation does not return a value (or the return has no meaning) You should use Java Lang.void as a type parameter

new Callable<Void>() {

  public Void call() throws Exception {
    // do work
    return null; // <-- This statement is required.
  }

}