add:  if(!requestNeeded) { return Divmod.Defer.succeed(1); } 
context:     function _getSomeRows(self) {        var scrollViewportHeight = self._scrollViewport.clientHeight;        if(!scrollViewportHeight) {            scrollViewportHeight = parseInt(self._scrollViewport.style.height);        }        if(!scrollViewportHeight) {            scrollViewportHeight = 400;        }        var desiredRowCount = Math.ceil(scrollViewportHeight / self._rowHeight);        var firstRow = Math.floor(self._scrollViewport.scrollTop / self._rowHeight);        var requestNeeded = false;        for (var i = 0; i < desiredRowCount; i++) {            if (typeof self._rows[firstRow] === 'undefined') {                requestNeeded = true;                break;            }            firstRow++;        }        if (!requestNeeded) {            return Divmod.Defer.succeed(1);        }        /* do we have the rows we need ? */        return self.callRemote("requestRowRange", firstRow, firstRow + desiredRowCount).addCallback(            function(rowData) {                return self.createRows(firstRow, rowData);            });    },
meta: 3455	/local1/tlutelli/issta_data/temp/all_js/javascript/2006_temp/2006/3455/f2dee7828b4655edee1c6d2bdc288b4e1b2f95c6/scrolltable.js/clean/xmantissa/static/js/scrolltable.js