Bug 72615 [Viewers] Need and ITableFontProvider
We released an ITabelColorProvider for M2 - we should have a corresponding ITableFontProvider
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
if (needDummy && !haveDummy) {
                    newItem(ti, SWT.NULL, -1);
                } else {
                    
                    tree.redraw();
                }
                return;
            }
        }
        if (childElements.length > 0) {
            Object[] filtered = filter(childElements);
            for (int i = 0; i < filtered.length; i++) {
                createAddedElement(widget, filtered[i]);
            }
        }
    }
    /**
     * Create the new element in the parent widget. If the
     * child already exists do nothing.
     * @param widget
     * @param element
     */
    private void createAddedElement(Widget widget, Object element) {
        if (equals(element, widget.getData()))
            return;
        Item[] items = getChildren(widget);
        for (int i = 0; i < items.length; i++) {
            if (items[i].getData().equals(element))
                return;
        }