How to use the gitman.shell.cd function in gitman

def get_top_level_dependencies(self):
        """Yield the path, repository, and hash of top-level dependencies."""
        if not os.path.exists(self.location_path):
            return

        shell.cd(self.location_path)
        common.newline()
        common.indent()

        for source in self.sources:

            yield os.path.join(self.location_path, source.name)

            shell.cd(self.location_path, _show=False)

        common.dedent()

if source.name not in sources_filter:
                log.info("Skipped dependency: %s", source.name)
                continue

            source_locked = source.lock(skip_changes=skip_changes)

            if source_locked is not None:
                try:
                    index = self.sources_locked.index(source)
                except ValueError:
                    self.sources_locked.append(source_locked)
                else:
                    self.sources_locked[index] = source_locked
                count += 1

            shell.cd(self.location_path, _show=False)

        if count:
            self.save()

        common.dedent()

        return count

def uninstall_dependencies(self):
        """Delete the dependency storage location."""
        shell.cd(self.root)
        shell.rm(self.location_path)
        common.newline()

if depth == 0:
                log.info("Skipped dependency: %s", source.name)
                continue

            yield source.identify(allow_dirty=allow_dirty)

            config = load_config(search=False)
            if config:
                common.indent()
                yield from config.get_dependencies(
                    depth=None if depth is None else max(0, depth - 1),
                    allow_dirty=allow_dirty,
                )
                common.dedent()

            shell.cd(self.location_path, _show=False)

        common.dedent()

config = load_config(search=False)
            if config:
                common.indent()
                count += config.install_dependencies(
                    depth=None if depth is None else max(0, depth - 1),
                    update=update and recurse,
                    recurse=recurse,
                    force=force,
                    fetch=fetch,
                    clean=clean,
                    skip_changes=skip_changes,
                )
                common.dedent()

            shell.cd(self.location_path, _show=False)

        common.dedent()
        if sources_filter:
            log.error("No such dependency: %s", ' '.join(sources_filter))
            return 0

        return count