Bug 299536 API refers to non-API type UIResourceFilterDescription
I20100112 CreateGroupOperation and CreateFolderOperation have constructors that require a UIResourceFilterDescription[]. However this is a non-API type, so clients can't reference it without using internals. Either the constructor should be removed or something like UIResourceFilterDescription needs to be promoted to API. Also, shouldn't CreateFolderOperation be renamed CreateVirtualFolderOperation?
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/dialogs/ResourceFilterGroup.java
int size = readIn.readInt();
					LinkedList droppedFilters = new LinkedList();
					for (int i = 0; i < size; i++) {
						int serialNumber = readIn.readInt();
						FilterCopy tmp = filters
								.findBySerialNumber(serialNumber);
						if (tmp != null)
							droppedFilters.add(tmp);
					}
					myData = (FilterCopy[]) droppedFilters
							.toArray(new FilterCopy[0]);
					readIn.close();
				} catch (IOException ex) {
					return null;
				}
				return myData;
			}
			return null;
		}
		private final String MYTYPENAME = "org.eclipse.ui.ide.internal.filterCopy"; 
		private final int MYTYPEID = registerType(MYTYPENAME);
		protected String[] getTypeNames() {
			return new String[] { MYTYPENAME };
		}
		protected int[] getTypeIds() {
			return new int[] { MYTYPEID };
		}
	}
}
class FilterTypeUtil {