Bug 75711 AstProvider should not create AST if requested by SelectionListenerWithASTManager
3.1 M2 If SelectionListenerWithASTManager waits for an AST and the editor closes we should not create an AST for that one but return null instead.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/ClipboardOperationAction.java
* @see org.eclipse.swt.dnd.Transfer#javaToNative(java.lang.Object, org.eclipse.swt.dnd.TransferData)
		 */
		protected void javaToNative(Object data, TransferData transferData) {
			if (data instanceof ClipboardData) {
				try {
					super.javaToNative(((ClipboardData) data).serialize(), transferData);
				} catch (IOException e) {
					
				}
			}
		}
		/* (non-Javadoc)
		 * Method declared on Transfer.
		 */
		protected Object nativeToJava(TransferData transferData) {
			byte[] bytes = (byte[]) super.nativeToJava(transferData);
			if (bytes != null) {
				try {
					return new ClipboardData(bytes);
				} catch (IOException e) {
				}
			}
			return null;
		}
	}
	private static final ClipboardTransfer fgTransferInstance = new ClipboardTransfer();
	
	
	private int fOperationCode= -1;