code: function(obj)
  	{
  		if (obj != null)
  		{
  			if (obj[mxObjectIdentity.FIELD_NAME] == null)
  			{
  				if (typeof obj === 'object')
  				{
  					var ctor = mxUtils.getFunctionName(obj.constructor);
  					obj[mxObjectIdentity.FIELD_NAME] = ctor + '#' + mxObjectIdentity.counter++;
  				}
  				else if (typeof obj === 'function')
  				{
  					obj[mxObjectIdentity.FIELD_NAME] = 'Function#' + mxObjectIdentity.counter++;
  				}
  			}
  			
  			return obj[mxObjectIdentity.FIELD_NAME];
  		}
  		
  		return null;
  	}
docs: Function: get
  
  Returns the ID for the given object or function or null if no object
  is specified.