How to use the hdfs.client.Client.from_options function in hdfs

def test_autoload_client_from_module(self):
    with temppath() as module_dpath:
      os.mkdir(module_dpath)
      sys.path.append(module_dpath)
      module_fpath = osp.join(module_dpath, 'mclient.py')
      self._write_client_module(module_fpath, 'ModuleClient')
      try:
        with temppath() as config_path:
          config = Config(config_path)
          config.add_section(config.global_section)
          config.set(config.global_section, 'autoload.modules', 'mclient')
          config._autoload()
          client = Client.from_options({'url': ''}, 'ModuleClient')
          eq_(client.one, 1)
      finally:
        sys.path.remove(module_dpath)

def test_autoload_client_from_path(self):
    with temppath() as module_path:
      self._write_client_module(module_path, 'PathClient')
      with temppath() as config_path:
        config = Config(config_path)
        config.add_section(config.global_section)
        config.set(config.global_section, 'autoload.paths', module_path)
        config._autoload()
        client = Client.from_options({'url': ''}, 'PathClient')
        eq_(client.one, 1)

not self.has_section(self.global_section) or
        not self.has_option(self.global_section, 'default.alias')
      ):
        raise HdfsError('No alias specified and no default alias found.')
      alias = self.get(self.global_section, 'default.alias')
    if not alias in self._clients:
      for suffix in ('.alias', '_alias'):
        section = '%s%s' % (alias, suffix)
        if self.has_section(section):
          options = dict(self.items(section))
          class_name = options.pop('client', 'InsecureClient')
          # Massage options.
          if 'timeout' in options:
            timeout = tuple(int(s) for s in options['timeout'].split(','))
            options['timeout'] = timeout[0] if len(timeout) == 1 else timeout
          self._clients[alias] = Client.from_options(options, class_name)
          break
      else:
        raise HdfsError('Alias %r not found in %r.', alias, self.path)
    return self._clients[alias]