def execute(self, callback=None):
        # Preprocess options to extract --settings and --pythonpath.
        # These options could affect the commands that are available, so they
        # must be processed early.
        self.parser = parser = NewOptionParser(prog=self.prog_name,
                             usage=self.usage_info,
#                             version=self.get_version(),
                             formatter = NewFormatter(),
                             add_help_option = False,
                             option_list=self.option_list)
        
        if not self.global_options:
            global_options, args = parser.parse_args(self.argv)
            global_options.apps_dir = os.path.normpath(os.path.join(global_options.project, 'apps'))
            handle_default_options(global_options)
            args = args[1:]
        else:
            global_options = self.global_options
            args = self.argv

        if global_options.envs:
            for x in global_options.envs:
                if '=' in x:
                    k, v = x.split('=')
                    os.environ[k.strip()] = v.strip()
                else:
                    print ('Error: environment variable definition (%s) format is not right, '
                           'shoule be -Ek=v or -Ek="a b"' % x)

        global_options.settings = global_options.settings or os.environ.get('SETTINGS', 'settings.ini')
        global_options.local_settings = global_options.local_settings or os.environ.get('LOCAL_SETTINGS', 'local_settings.ini')
        
        if callback:
            callback(global_options)
            
        if len(args) == 0:
            if global_options.version:
                print self.get_version()
                sys.exit(0)
            else:
                self.print_help(global_options)
                sys.ext(1)

        self.do_command(args, global_options)
bg_image should always be in the form returned from api.background_upload.
dataset/ETHPy150Open limodou/uliweb/uliweb/core/commands.py/CommandManager.execute--crossover with--dataset/ETHPy150Open CollabQ/CollabQ/common/clean.py/bg_image