Clone and composer install.
git clone https://github.com/yuichiro12/php-spanner-deadlock-example.git
cd php-spanner-deadlock-example
composer install
Set up environment variables $GOOGLE_APPLICATION_CREDENTIALS and $TEST_SPANNER_INSTANCE_ID.
export GOOGLE_APPLICATION_CREDENTIALS=/path/to/credential.json
export TEST_SPANNER_INSTANCE_ID=<SPANNER_INSTANCE_ID>
php test.php