def update(self, folder, git_repository):
<EOL>try:<EOL><INDENT>self.clone(folder, git_repository)<EOL><DEDENT>except OSError:<EOL><INDENT>self.update_git_repository(folder, git_repository)<EOL>self.pull(folder)<EOL><DEDENT>
Creates or updates theme folder according given git repository.

        :param git_repository: git url of the theme folder
        :param folder: path of the git managed theme folder