code: public boolean contains(Interval<T> another){
  		if (another == null || isEmpty() || another.isEmpty()){
  			return false;
  		}
  		Interval<T> intersection = getIntersection(another);
  		return intersection != null && intersection.equals(another);
  	}
docs: Checks if the current interval contains the entirety of another interval. More formally,
  this method returns {@code true}, if for every point {@code x} from the interval {@code another}
  this point {@code x} also belongs to the current interval.
  
  @param another Another interval.
  @return {@code true}, if the interval {@code another} is contained in the current interval in
  its entirety, or {@code false} otherwise.