private void initVertices(Iterator<Point> it, int size) 
			throws NullArgumentException, BadPointException {
		this.vertices = new Vector<Point>();
		this.vertices.setSize(size);
		int idx = 0;
		while( it.hasNext() )
		{
			Point tempPoint = it.next();
			if (tempPoint == null)
				throw new NullArgumentException("Point");
			if (!tempPoint.isValid()) 
				throw new BadPointException();
			this.vertices.set( idx++, new Point(tempPoint) );
		}
	}