code: protected static <T> CircularElement<T> spillingMarker() {
  		@SuppressWarnings("unchecked")
  		CircularElement<T> c = (CircularElement<T>) SPILLING_MARKER;
  		return c;
  	}
docs: Gets the element that is passed as marker for signal beginning of spilling.
  
  @return The element that is passed as marker for signal beginning of spilling.