def init_app(self, app):
        """Initialize the extension."""
        # Set default Flask config option.
        app.config.setdefault('STATICS_MINIFY', False)

        # Select resources.
        self.all_resources = ALL_RESOURCES_MINIFIED if app.config.get('STATICS_MINIFY') else ALL_RESOURCES
        self.all_variables = ALL_VARIABLES

        # Add this instance to app.extensions.
        if not hasattr(app, 'extensions'):
            app.extensions = dict()
        if 'statics' in app.extensions:
            raise ValueError('Already registered extension STATICS.')
        app.extensions['statics'] = _StaticsState(self, app)

        # Initialize blueprint.
        name = 'flask_statics_helper'
        static_url_path = '{0}/{1}'.format(app.static_url_path, name)
        self.blueprint = Blueprint(name, __name__, template_folder='templates', static_folder='static',
                                   static_url_path=static_url_path)
        self.blueprint.add_app_template_global(self.all_variables, '_flask_statics_helper_all_variables')
        self.blueprint.add_app_template_global(self.all_resources, '_flask_statics_helper_all_resources')
        app.register_blueprint(self.blueprint)
Initialize the extension.