private void mockYarnVcapServiceReader() {
   when(yarnVcapServiceReader.getConfigZipFiles()).thenReturn(correctBase64FilesContent);
 }
 @Test(expected = IOException.class)
 public void testPrepareConfigFilesThrowsExceptionWithWrongBase64FileContent() throws IOException {
   when(yarnVcapServiceReader.getConfigZipFiles()).thenReturn(inCorrectBase64FilesContent);
   yarnConfigFilesProvider.prepareConfigFiles();
 }