def load_pip_requirements(self, files_map=None, freeze=True):
        if files_map is None:
            files_map = self.default_pip_files
        for group, requirements_txt in files_map.items():
            path = Path(requirements_txt)
            if not path.exists() and group.lower() == "all" and freeze:
                cmd = envoy.run("pip freeze")
                self[group].loads(cmd.std_out)
            elif path.exists():
                self[group].load(path)
def switch(self, dest, url, rev_options):
        # type: (str, HiddenText, RevOptions) -> None
        self.run_command(
            make_command('config', 'remote.origin.url', url),
            cwd=dest,
        )
        cmd_args = make_command('checkout', '-q', rev_options.to_args())
        self.run_command(cmd_args, cwd=dest)

        self.update_submodules(dest)