var (
	// UnitTestRunner only runs in `--short` mode, will fail otherwise. Attempts in cluster creation will result in tests being skipped.
	UnitTestRunner intf.TestRunner = unit.NewUnitRunner()
	// E2eTestRunner runs etcd and etcdctl binaries in a separate process.
	E2eTestRunner = e2e.NewE2eRunner()
	// IntegrationTestRunner runs etcdserver.EtcdServer in separate goroutine and uses client libraries to communicate.
	IntegrationTestRunner = integration.NewIntegrationRunner()
)