Bug 63901

Hi,
When I want import the srcChart to the new drawing. 
Method XSSFDrawing.importChart(XSSFChart srcChart) throws org.apache.xmlbeans.impl.values.XmlValueDisconnectedException. Maybe I do something wrong. This is my code snippet: 

Workbook workbook = new XSSFWorkbook(new File("/test.xlsx"));
Sheet sheet = workbook.getSheet("Arkusz1");
XSSFDrawing drawing = ((XSSFSheet)sheet).createDrawingPatriarch();

Workbook workbook2 = new XSSFWorkbook(new File("/test2.xlsx"));
Sheet sheet2 = workbook2.getSheet("Arkusz1");
XSSFDrawing drawing2 = ((XSSFSheet)sheet2).createDrawingPatriarch();

drawing
   .getCharts()
   .forEach(xssfChart -> {
          try {
               drawing2.importChart(xssfChart);
           } catch (IOException e) {
               e.printStackTrace();
          } catch (XmlException e) {
               e.printStackTrace();
      }
   });

This is very strange and I don't see any solution.
I read some about this exception and he is thrown when try to write more then one time the same workbook. These two lines generate exception.

destChart.getCTChartSpace().set(srcChart.getCTChartSpace().copy());
destChart.getCTChart().set(srcChart.getCTChart().copy());

When I do this on the same workbook I have the same result.

Did I do something wrong or this is a bug? This is my first post in ASF Bugzilla.
Thx