code: def mkdir(self, parent, name):
          
          pid = None
          cid = None
          if isinstance(parent, Directory):
              pid = parent.cid
          else:
              raise('Invalid Directory instance.')
          cid = self._req_files_add(pid, name)['cid']
          return self._load_directory(cid)
docs: Create a directory
  
          :param parent: the parent directory
          :param str name: the name of the new directory
          :return: the new directory
          :rtype: :class:`.Directory`