new_contents: import logging
  logger = logging.getLogger('pcm')
  
  from pcm.cmds.base import BaseCmd
  from pcm.lib.cmd import PacmanCmd
  
  
  class Cmd(BaseCmd):
      """Docstring for Cmd """
  
      name = 'update'
      help_text = ("update pkgname [pkgnames...]")
      aliases = ('up',)
  
      def build(self):
          """todo: Docstring for build
          :return:
          :rtype:
          """
  
          self._cmd_parser.add_argument(
              'pkgs',
              type=str,
              default=None,
              nargs="*",
              help=(""),
          )
  
          return super(Cmd, self).build()
      # build()
  
      def exec(self, args):
          """todo: Docstring for exec
  
          :param args: arg description
          :type args: type description
          :return:
          :rtype:
          """
  
          logger.debug("pkgs %s", args.pkgs)
          update = UpdateCmd(*args.pkgs)
          update.execute()
      # exec()
  # Cmd
  
  
  class UpdateCmd(PacmanCmd):
      pacman_args = ('-Su',)
  
      def __init__(self, *pkgs):
          """todo: to be defined
  
          :param *pkgs: arg description
          :type *pkgs: type description
          """
          super(UpdateCmd, self).__init__(*pkgs)
      # __init__()
  # UpdateCmd
  
subject: Add update command.