code: function _fnApplyToChildren( fn, an1, an2 )
  	{
  		var index=0, i=0, iLen=an1.length;
  		var nNode1, nNode2;
  	
  		while ( i < iLen ) {
  			nNode1 = an1[i].firstChild;
  			nNode2 = an2 ? an2[i].firstChild : null;
  	
  			while ( nNode1 ) {
  				if ( nNode1.nodeType === 1 ) {
  					if ( an2 ) {
  						fn( nNode1, nNode2, index );
  					}
  					else {
  						fn( nNode1, index );
  					}
  	
  					index++;
  				}
  	
  				nNode1 = nNode1.nextSibling;
  				nNode2 = an2 ? nNode2.nextSibling : null;
  			}
  	
  			i++;
  		}
  	}
docs: Apply a given function to the display child nodes of an element array (typically
  TD children of TR rows
  @param {function} fn Method to apply to the objects
  @param array {nodes} an1 List of elements to look through for display children
  @param array {nodes} an2 Another list (identical structure to the first) - optional
  @memberof DataTable#oApi