code: function mxArrow(points, fill, stroke, strokewidth, arrowWidth, spacing, endSize)
  {
  	mxShape.call(this);
  	this.points = points;
  	this.fill = fill;
  	this.stroke = stroke;
  	this.strokewidth = (strokewidth != null) ? strokewidth : 1;
  	this.arrowWidth = (arrowWidth != null) ? arrowWidth : mxConstants.ARROW_WIDTH;
  	this.spacing = (spacing != null) ? spacing : mxConstants.ARROW_SPACING;
  	this.endSize = (endSize != null) ? endSize : mxConstants.ARROW_SIZE;
  }
docs: Copyright (c) 2006-2015, JGraph Ltd
  Copyright (c) 2006-2015, Gaudenz Alder
   
  Class: mxArrow
  
  Extends <mxShape> to implement an arrow shape. (The shape
  is used to represent edges, not vertices.)
  This shape is registered under <mxConstants.SHAPE_ARROW>
  in <mxCellRenderer>.
  
  Constructor: mxArrow
  
  Constructs a new arrow shape.
  
  Parameters:
  
  points - Array of <mxPoints> that define the points. This is stored in
  <mxShape.points>.
  fill - String that defines the fill color. This is stored in <fill>.
  stroke - String that defines the stroke color. This is stored in <stroke>.
  strokewidth - Optional integer that defines the stroke width. Default is
  1. This is stored in <strokewidth>.
  arrowWidth - Optional integer that defines the arrow width. Default is
  <mxConstants.ARROW_WIDTH>. This is stored in <arrowWidth>.
  spacing - Optional integer that defines the spacing between the arrow shape
  and its endpoints. Default is <mxConstants.ARROW_SPACING>. This is stored in
  <spacing>.
  endSize - Optional integer that defines the size of the arrowhead. Default
  is <mxConstants.ARROW_SIZE>. This is stored in <endSize>.