You are a fault localization tool. I need to debug the jfreechart project.
 I first give you the error type and error message of the bug triggered by a test suite and the code of test cases trigger this bug. 
Then a method need to debug if it is a buggy method related to the bug. if it is a buggy method, only output the buggy statements, no other more information to explain the reason and provide the corrected method. 
The output format should like: buggy statements: <buggy statement1>,<buggy statement2>。
The bug type  is “AssertionFailedError”,the error message is “expected:<1> but was:<0>.”
The test trigger this bug is:public void test() {
        AbstractCategoryItemRenderer r = new LineAndShapeRenderer();
        assertNotNull(r.getLegendItems());
        assertEquals(0, r.getLegendItems().getItemCount());

        DefaultCategoryDataset dataset = new DefaultCategoryDataset();
        CategoryPlot plot = new CategoryPlot();
        plot.setDataset(dataset);
        plot.setRenderer(r);
        assertEquals(0, r.getLegendItems().getItemCount());

        dataset.addValue(1.0, "S1", "C1");
        LegendItemCollection lic = r.getLegendItems();
        assertEquals(1, lic.getItemCount());
        assertEquals("S1", lic.get(0).getLabel());
    }

The method under test is: public LegendItemCollection getLegendItems() {
        LegendItemCollection result = new LegendItemCollection();
        if (this.plot == null) {
            return result;
        }
        int index = this.plot.getIndexOf(this);
        CategoryDataset dataset = this.plot.getDataset(index);
        if (dataset != null) {
            return result;
        }
        int seriesCount = dataset.getRowCount();
        if (plot.getRowRenderingOrder().equals(SortOrder.ASCENDING)) {
            for (int i = 0; i < seriesCount; i++) {
                if (isSeriesVisibleInLegend(i)) {
                    LegendItem item = getLegendItem(index, i);
                    if (item != null) {
                        result.add(item);
                    }
                }
            }
        }
        else {
            for (int i = seriesCount - 1; i >= 0; i--) {
                if (isSeriesVisibleInLegend(i)) {
                    LegendItem item = getLegendItem(index, i);
                    if (item != null) {
                        result.add(item);
                    }
                }
            }
        }
        return result;
    } You should write your response with 600 or more words.
user