How to use the mkdocs.exceptions.ConfigurationError function in mkdocs

config = DEFAULT_CONFIG.copy()

    theme_in_config = 'theme' in user_config

    config.update(user_config)

    if not config['site_name']:
        raise ConfigurationError("Config must contain 'site_name' setting.")

    # Validate that the docs_dir and site_dir don't contain the
    # other as this will lead to copying back and forth on each
    # and eventually make a deep nested mess.
    abs_site_dir = os.path.abspath(config['site_dir'])
    abs_docs_dir = os.path.abspath(config['docs_dir'])
    if abs_docs_dir.startswith(abs_site_dir):
        raise ConfigurationError(
            "The 'docs_dir' can't be within the 'site_dir'.")
    elif abs_site_dir.startswith(abs_docs_dir):
        raise ConfigurationError(
            "The 'site_dir' can't be within the 'docs_dir'.")

    # If not specified, then the 'pages' config simply includes all
    # markdown files in the docs dir, without generating any header items
    # for them.
    pages = []
    extra_css = []
    extra_javascript = []
    extra_templates = []
    for (dirpath, _, filenames) in os.walk(config['docs_dir']):
        for filename in sorted(filenames):
            fullpath = os.path.join(dirpath, filename)
            relpath = os.path.normpath(os.path.relpath(fullpath, config['docs_dir']))

page = Page(title, path, url_context, config)

        if header:
            page.ancestors = header.ancestors + [header, ]
            header.children.append(page)

        yield page
        raise StopIteration

    elif not isinstance(config_line, dict):
        msg = ("Line in 'page' config is of type {0}, dict or string "
               "expected. Config: {1}").format(type(config_line), config_line)
        raise exceptions.ConfigurationError(msg)

    if len(config_line) > 1:
        raise exceptions.ConfigurationError(
            "Page configs should be in the format 'name: markdown.md'. The "
            "config contains an invalid entry: {0}".format(config_line))
    elif len(config_line) == 0:
        log.warning("Ignoring empty line in the pages config.")
        raise StopIteration

    next_cat_or_title, subpages_or_path = next(iter(config_line.items()))

    if isinstance(subpages_or_path, utils.string_types):
        path = subpages_or_path
        for sub in _follow(path, url_context, config, header=header, title=next_cat_or_title):
            yield sub
        raise StopIteration

    elif not isinstance(subpages_or_path, list):
        msg = ("Line in 'page' config is of type {0}, list or string "

def validate_config(user_config):
    config = DEFAULT_CONFIG.copy()

    theme_in_config = 'theme' in user_config

    config.update(user_config)

    if not config['site_name']:
        raise ConfigurationError("Config must contain 'site_name' setting.")

    # Validate that the docs_dir and site_dir don't contain the
    # other as this will lead to copying back and forth on each
    # and eventually make a deep nested mess.
    abs_site_dir = os.path.abspath(config['site_dir'])
    abs_docs_dir = os.path.abspath(config['docs_dir'])
    if abs_docs_dir.startswith(abs_site_dir):
        raise ConfigurationError(
            "The 'docs_dir' can't be within the 'site_dir'.")
    elif abs_site_dir.startswith(abs_docs_dir):
        raise ConfigurationError(
            "The 'site_dir' can't be within the 'docs_dir'.")

    # If not specified, then the 'pages' config simply includes all
    # markdown files in the docs dir, without generating any header items
    # for them.

def load_dict(self, patch):

        if not isinstance(patch, dict):
            raise exceptions.ConfigurationError(
                "The configuration is invalid. The expected type was a key "
                "value mapping (a python dict) but we got an object of type: "
                "{}".format(type(patch)))

        self.user_configs.append(patch)
        self.data.update(patch)