* Copyright (c) 2004 World Wide Web Consortium,
* (Massachusetts Institute of Technology, European Research Consortium for
* Informatics and Mathematics, Keio University). All Rights Reserved. This
* work is distributed under the W3C(r) Software License  in the hope that
* it will be useful, but WITHOUT ANY WARRANTY; without even the implied
* warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*  http://www.w3.org/Consortium/Legal/2002/copyright-software-20021231
Node.setUserData()the application can provide a handler that gets called when the node the object is associated to is being cloned, imported, or renamed. This can be used by the application to implement various behaviors regarding the data it associates to the DOM nodes. This interface defines that handler.
See also the.
UserDataHandler. The effect of throwing exceptions from the handler is DOM implementation dependent.
operationSpecifies the type of operation that is being performed on the node.
keySpecifies the key for which this handler is being called.
dataSpecifies the data for which this handler is being called.
srcSpecifies the node being cloned, adopted, imported, or renamed. This is
nullwhen the node is being deleted.
dstSpecifies the node newly created if any, or