@Test
	public void testZSS4xxx(){
		Book book = Util.loadBook(Issue400Test.class, "book/blank.xlsx");
		Sheet sheet = book.getSheetAt(0);
		Ranges.range(sheet, "A1").setCellEditText("http://www.google.com");
		Ranges.range(sheet, "A2").setCellEditText("http://www.zkoss.org");
		
		Hyperlink link = Ranges.range(sheet, "A1").getCellHyperlink();
		Assert.assertNotNull(link);
		Assert.assertEquals(Hyperlink.HyperlinkType.URL,link.getType());
		Assert.assertEquals(link.getAddress(), "http://www.google.com");
		Assert.assertEquals(link.getLabel(), "http://www.google.com");
		
		link = Ranges.range(sheet, "A2").getCellHyperlink();
		Assert.assertNotNull(link);
		Assert.assertEquals(Hyperlink.HyperlinkType.URL,link.getType());
		Assert.assertEquals(link.getAddress(), "http://www.zkoss.org");
		Assert.assertEquals(link.getLabel(), "http://www.zkoss.org");
		
		book = Util.swap(book);
		
		sheet = book.getSheetAt(0);
		link = Ranges.range(sheet, "A1").getCellHyperlink();
		Assert.assertNotNull(link);
		Assert.assertEquals(Hyperlink.HyperlinkType.URL,link.getType());
		Assert.assertEquals(link.getAddress(), "http://www.google.com");
		Assert.assertEquals(link.getLabel(), "http://www.google.com");
		
		link = Ranges.range(sheet, "A2").getCellHyperlink();
		Assert.assertNotNull(link);
		Assert.assertEquals(Hyperlink.HyperlinkType.URL,link.getType());
		Assert.assertEquals(link.getAddress(), "http://www.zkoss.org");
		Assert.assertEquals(link.getLabel(), "http://www.zkoss.org");
		
		Ranges.range(sheet, "A1").clearContents();
		
		Util.export(book, Setup.getTempFile());//get error if has this line
		
		link = Ranges.range(sheet, "A1").getCellHyperlink();
		Assert.assertNull(link);
		
		link = Ranges.range(sheet, "A2").getCellHyperlink();
		Assert.assertNotNull(link);
		Assert.assertEquals(Hyperlink.HyperlinkType.URL,link.getType());
		Assert.assertEquals(link.getAddress(), "http://www.zkoss.org");
		Assert.assertEquals(link.getLabel(), "http://www.zkoss.org");
		
	}

org.apache.xmlbeans.impl.values.XmlValueDisconnectedException
	at org.apache.xmlbeans.impl.values.XmlObjectBase.check_orphaned(XmlObjectBase.java:1213)
	at org.openxmlformats.schemas.spreadsheetml.x2006.main.impl.CTHyperlinkImpl.getRef(Unknown Source)
	at org.zkoss.poi.xssf.usermodel.XSSFHyperlink.getCellRef(XSSFHyperlink.java:138)
	at org.zkoss.poi.xssf.usermodel.XSSFSheet.getHyperlink(XSSFSheet.java:621)
	at org.zkoss.poi.xssf.usermodel.XSSFCell.getHyperlink(XSSFCell.java:910)
	at org.zkoss.poi.xssf.usermodel.XSSFCell.getHyperlink(XSSFCell.java:1)
	at org.zkoss.zss.model.sys.impl.BookHelper.getHyperlink(BookHelper.java:1016)
	at org.zkoss.zss.model.sys.impl.XRangeImpl.getHyperlink(XRangeImpl.java:161)
	at org.zkoss.zss.api.impl.RangeImpl.getCellHyperlink(RangeImpl.java:635)
	at org.zkoss.zss.api.impl.Issue400Test.testZSS4xxx(Issue400Test.java:1056)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
	at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
	at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:27)
	at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
	at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
	at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
	at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
	at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
	at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
	at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:26)
	at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
	at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
	at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)