code: def epubcheck(epubname, config=None):
      
      if config is None:
          config = load_config_module()
      r, e = os.path.splitext(epubname)
      if not e:
          log.warning('Missing file extension, appending ".epub"')
          e = '.epub'
          epubname = r + e
      elif not e == '.epub':
          log.warning('File does not have ".epub" extension, appending it')
          epubname += '.epub'
      subprocess.call(['java', '-jar', config.epubcheck_jarfile, epubname])
docs: This method takes the name of an epub file as an argument. This name is
      the input for the java execution of a locally installed epubcheck-.jar. The
      location of this .jar file is configured in config.py.