code: @Pure
  	public static <T> int getInsertionIndex(List<T> list, Comparator<? super T> comparator, T elt) {
  		return getInsertionIndex(list, comparator, elt, true);
  	}
docs: Replies the index at which the given element may
  be added in a sorted list.
  
  <p>This function assumes that the given list is sorted
  according to the given comparator.
  A dichotomic algorithm is used.
  
  <p>This function assumes that the given {@code elt}
  may appear many times in the list.
  
  @param <T> is the type of the elements.
  @param comparator is the comparator used to sort the list.
  @param elt is the element to add in.
  @param list is the list inside which the element should be added.
  @return the index at which the element may be added.