providers[ $name ] ) ) { return false; } $provider = apply_filters( 'wp_sitemaps_add_provider', $provider, $name ); if ( ! $provider instanceof WP_Sitemaps_Provider ) { return false; } $this->providers[ $name ] = $provider; return true; } public function get_provider( $name ) { if ( ! is_string( $name ) || ! isset( $this->providers[ $name ] ) ) { return null; } return $this->providers[ $name ]; } public function get_providers() { return $this->providers; } }