code: function mxChildChange(model, parent, child, index)
  {
  	this.model = model;
  	this.parent = parent;
  	this.previous = parent;
  	this.child = child;
  	this.index = index;
  	this.previousIndex = index;
  }
docs: Class: mxChildChange
  
  Action to add or remove a child in a model.
  
  Constructor: mxChildChange
  
  Constructs a change of a child in the
  specified model.