code: def addbr(self, name):
          
          _runshell([brctlexe, 'addbr', name],
              "Could not create bridge %s." % name)
          _runshell([ipexe, 'link', 'set', 'dev', name, 'up'],
              "Could not set link up for %s." % name)
          return Bridge(name)
docs: Create a bridge and set the device up.