def __git_add(args=''):
        """
        Add files to staging.
        The function call will return 0 if the command success.
        """
        command = ['git', 'add', '.']
        Shell.msg('Adding files...')

        if APISettings.DEBUG:
            Git.__debug(command, True)

        for key in args:
            command.append(key)
        if not call(command):
            pass
        return False
Add files to staging.
        The function call will return 0 if the command success.