code: public final int insertPointAt(Point2D<?, ?> point, int indexGroup, int indexInGroup) {
  		return insertPointAt(point.getX(), point.getY(), indexGroup, indexInGroup);
  	}
docs: Insert the specified point at the given index in the specified group.
  
  @param point is the point to insert
  @param indexGroup is the index of the group
  @param indexInGroup is the index of the ponit in the group (0 for the
  first point of the group...).
  @return the index of the new point in the element.
  @throws IndexOutOfBoundsException in case of error.