"Generate hashCode()" generates code like:

    this.field != null ? this.field.hashCode() : 0

It is generally preferable to express logical conditions without negation when there is the choice. (There are 
situations where there is no choice, such as an 'if' on a negative condition whith no 'else' branch. But this is not 
the case here.) I'd like to suggest to generate

    this.field == null ? 0 : this.field.hashCode()

instead. Besides getting rid of the (double) negation ("is not not an object"), it also places the simple case ("0") 
first, which minimizes the mental stack when reading such code.