Which of the following statements are true?
1)The hashCode method of an object can return any primitive integral type
2) If two objects are equal according to the equals(Object) method, calling the hashCode method on each of the objects must produce the same result.
3) The hashcode method of an object must return the same value consistently from one execution of an application to another.
4) The signature of the hashcode method of the Object class is public int hashCode()