protected function get_cookie() {

		$value = isset( $_COOKIE[ $this->cookie ] ) ? sanitize_text_field( wp_unslash( $_COOKIE[ $this->cookie ] ) ) : false;

		if ( empty( $value ) || ! is_string( $value ) ) {
			return false;
		}

		/**
		 * Explode the cookie into it's parts.
		 *
		 * @param string|int $0 User ID.
		 * @param int        $1 Expiration timestamp.
		 * @param int        $2 Expiration variance timestamp.
		 * @param string     $3 Cookie hash.
		 */
		$parts = explode( '||', $value );

		if ( empty( $parts[0] ) || empty( $parts[3] ) ) {
			return false;
		}

		$hash_str = sprintf( '%1$s|%2$s', $parts[0], $parts[1] );
		$expected = hash_hmac( 'md5', $hash_str, wp_hash( $hash_str ) );

		if ( ! hash_equals( $expected, $parts[3] ) ) {
			return false;
		}

		return $parts;

	}