How to use the dbt.clients.system function in dbt

def test__executable_does_not_exist(self):
        with self.assertRaises(ExecutableError) as exc:
            dbt.clients.system.run_cmd(self.run_dir, [self.does_not_exist])

        msg = str(exc.exception).lower()

        self.assertIn('path', msg)
        self.assertIn('could not find', msg)
        self.assertIn(self.does_not_exist.lower(), msg)

def test_git(self):
        try:
            dbt.clients.system.run_cmd(os.getcwd(), ['git', '--help'])
        except dbt.exceptions.ExecutableError as exc:
            self.messages.append('Error from git --help: {!s}'.format(exc))
            return red('ERROR')
        return green('OK found')

if tags is None:
            tags = []

        if dbt.flags.STRICT_MODE:
            dbt.contracts.project.ProjectList(**self.all_projects)

        file_matches = dbt.clients.system.find_matching(
            root_dir,
            relative_dirs,
            extension)

        result = []

        for file_match in file_matches:
            file_contents = dbt.clients.system.load_file_contents(
                file_match.get('absolute_path'))

            parts = dbt.utils.split_path(file_match.get('relative_path', ''))
            name, _ = os.path.splitext(parts[-1])

            path = self.get_compiled_path(name,
                                          file_match.get('relative_path'))

            original_file_path = os.path.join(
                file_match.get('searched_path'),
                path)

            result.append({
                'name': name,
                'root_path': root_dir,
                'resource_type': resource_type,

def install(self, project):
        dest_path = self.get_installation_path(project)
        if os.path.exists(dest_path):
            if dbt.clients.system.path_is_symlink(dest_path):
                dbt.clients.system.remove_file(dest_path)
            else:
                dbt.clients.system.rmdir(dest_path)
        dbt.clients.system.move(self._checkout(project), dest_path)

def install(self, project):
        version_string = self.version_name()
        metadata = self.fetch_metadata(project)

        tar_name = '{}.{}.tar.gz'.format(self.package, version_string)
        tar_path = os.path.realpath(os.path.join(DOWNLOADS_PATH, tar_name))
        dbt.clients.system.make_directory(os.path.dirname(tar_path))

        download_url = metadata['downloads']['tarball']
        dbt.clients.system.download(download_url, tar_path)
        deps_path = project.modules_path
        package_name = self.get_project_name(project)
        dbt.clients.system.untar_package(tar_path, deps_path, package_name)

def read_profile(profiles_dir):
    path = os.path.join(profiles_dir, 'profiles.yml')

    contents = None
    if os.path.isfile(path):
        try:
            contents = dbt.clients.system.load_file_contents(path, strip=False)
            return dbt.clients.yaml_helper.load_yaml_text(contents)
        except dbt.exceptions.ValidationException as e:
            msg = INVALID_PROFILE_MESSAGE.format(error_string=e)
            raise dbt.exceptions.ValidationException(msg)

    return {}

def get_addendum(self, project_name, profiles_path):
        open_cmd = dbt.clients.system.open_dir_cmd()

        return ON_COMPLETE_MESSAGE.format(
            open_cmd=open_cmd,
            project_name=project_name,
            profiles_path=profiles_path,
            docs_url=DOCS_URL
        )

def make_log_dir_if_missing(log_dir):
    import dbt.clients.system
    dbt.clients.system.make_directory(log_dir)