@Test
    public void testEmbeddedGraphChart() throws Exception {
        //docx converts a chart to a actual xlsx file
        //so we only need to look in pptx and xlsx
        for (String suffix : new String[]{"pptx", "xlsx"}) {
            List<Metadata> list = getRecursiveMetadata("testMSChart-govdocs-428996." + suffix);
            boolean found = false;
            for (Metadata m : list) {
                if (m.get(Metadata.CONTENT_TYPE)
                        .equals(POIFSContainerDetector.MS_GRAPH_CHART.toString())) {
                    found = true;
                }
                assertNull(m.get(TikaCoreProperties.EMBEDDED_EXCEPTION));
            }
            assertTrue(found, "didn't find chart in " + suffix);
        }
    }
Office files which have other office files
embedded into them. The embedded office files
will sometimes have images in them.
<p/>
eg xls
-> word
-> image
-> image
-> powerpoint
-> excel
-> image
tika-parsers/tika-parsers-standard/tika-parsers-standard-modules/tika-parser-microsoft-module/src/test/java/org/apache/tika/parser/microsoft/ooxml/OOXMLContainerExtractionTest.java