How to use the gabbi.utils.load_yaml function in gabbi

def run_suite(handle, handler_objects, host, port, prefix, force_ssl=False,
              failfast=False, data_dir='.', verbosity=False, name='input',
              safe_yaml=True, quiet=False, cert_validate=True):
    """Run the tests from the YAML in handle."""
    data = utils.load_yaml(handle, safe=safe_yaml)
    if force_ssl:
        if 'defaults' in data:
            data['defaults']['ssl'] = True
        else:
            data['defaults'] = {'ssl': True}
    if verbosity:
        if 'defaults' in data:
            data['defaults']['verbose'] = verbosity
        else:
            data['defaults'] = {'verbose': verbosity}
    if not cert_validate:
        if 'defaults' in data:
            data['defaults']['cert_validate'] = False
        else:
            data['defaults'] = {'cert_validate': False}

response_handlers = response_handlers or []
    content_handlers = content_handlers or []
    handler_objects = []
    for handler in (content_handlers + response_handlers +
                    handlers.RESPONSE_HANDLERS):
        handler_objects.append(handler())

    top_suite = suite.TestSuite()
    for test_file in glob.iglob('%s/*.yaml' % path):
        if '_' in os.path.basename(test_file):
            warnings.warn(exception.GabbiSyntaxWarning(
                "'_' in test filename %s. This can break suite grouping."
                % test_file))
        if intercept:
            host = str(uuid.uuid4())
        suite_dict = utils.load_yaml(yaml_file=test_file,
                                     safe=safe_yaml)
        test_base_name = os.path.splitext(os.path.basename(test_file))[0]
        if all_test_base_name:
            test_base_name = '%s_%s' % (all_test_base_name, test_base_name)

        if require_ssl:
            if 'defaults' in suite_dict:
                suite_dict['defaults']['ssl'] = True
            else:
                suite_dict['defaults'] = {'ssl': True}

        if any((verbose == opt for opt in [True, 'all', 'headers', 'body'])):
            if 'defaults' in suite_dict:
                suite_dict['defaults']['verbose'] = verbose
            else:
                suite_dict['defaults'] = {'verbose': verbose}

prefix = parsed_url.path.rstrip('/')  # turn it into a prefix
        if parsed_url.scheme == 'https':
            port = 443
            require_ssl = True
        else:
            port = 80
            require_ssl = False
        host = parsed_url.hostname
        if parsed_url.port:
            port = parsed_url.port

        os.environ["GNOCCHI_SERVICE_TOKEN"] = token
        os.environ["GNOCCHI_AUTHORIZATION"] = "not used"

        with open(os.path.join(TEST_DIR, filename)) as f:
            suite_dict = utils.load_yaml(f)
            suite_dict.setdefault('defaults', {})['ssl'] = require_ssl
            test_suite = suitemaker.test_suite_from_dict(
                loader=unittest.defaultTestLoader,
                test_base_name="gabbi",
                suite_dict=suite_dict,
                test_directory=TEST_DIR,
                host=host, port=port,
                fixture_module=None,
                intercept=None,
                prefix=prefix,
                handlers=runner.initialize_handlers([]),
                test_loader_name="tempest")

            # NOTE(sileht): We hide stdout/stderr and reraise the failure
            # manually, tempest will print it itself.
            with open(os.devnull, 'w') as stream: