Bug 293130 Polishing the Filter extension point
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/dialogs/ResourceFilterGroup.java
Object arguments = getArguments();
				if (arguments instanceof IResourceFilterDescription[]) {
					IResourceFilterDescription[] filters = (IResourceFilterDescription[]) arguments;
					if (filters != null)
						for (int i = 0; i < filters.length; i++) {
							FilterCopy child = new FilterCopy(UIResourceFilterDescription.wrap(filters[i]));
							child.parent = this;
							children.add(child);
						}
				}
			}
		}
	}
	public void addChild(FilterCopy child) {
		initializeChildren();
		if (child.getParent() != null)
			child.getParent().removeChild(child);
		children.add(child);
		child.parent = this;
		serializeChildren();
	}
	public void removeChild(FilterCopy child) {
		initializeChildren();
		children.remove(child);
		if (child.parent == this)
			child.parent = null;
		serializeChildren();
	}
	protected void serializeChildren() {
		initializeChildren();