Bug 5677 Hierarchy outline has empty space
I opened a hierarchy view on IActionDelegate. Selected a few of the subinterfaces, changed the expansion state of the tree. Then, no matter which item I selected in the top window (the hierarchy tree), the bottom window (the outline table) always had exactly four empty rows before the first item was listed.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/dialogfields/CheckedListDialogField.java
*/
	public boolean isChecked(Object obj) {
		return fCheckElements.contains(obj);
	}	
	
	/**
	 * Sets the checked elements.
	 */	
	public void setCheckedElements(List list) {
		fCheckElements= new ArrayList(list);
		if (fTable != null) {
			((CheckboxTableViewer)fTable).setCheckedElements(list.toArray());
		}
		checkStateChanged();
	}
	/**
	 * Sets the checked state of an element.
	 */		
	public void setChecked(Object object, boolean state) {
		setCheckedWithoutUpdate(object, state);
		checkStateChanged();
	}
	
	/**
	 * Sets the checked state of an element. no dialog changed listener informed
	 */		
	public void setCheckedWithoutUpdate(Object object, boolean state) {
		if (!fCheckElements.contains(object)) {
			fCheckElements.add(object);
		}