private static DataSource configureDataSource(DataSource existingDataSource) {
    if (existingDataSource instanceof TransactionAwareDataSourceProxy) {
      log.debug("Using an already transaction aware DataSource");
      return existingDataSource;
    }

    log.debug(
        "The configured DataSource is not transaction aware: '{}'. Wrapping in TransactionAwareDataSourceProxy.",
        existingDataSource);

    return new TransactionAwareDataSourceProxy(existingDataSource);
  }
Will typically be created if Spring Boot Actuator is not on the classpath.
db-scheduler-boot-starter/src/main/java/com/github/kagkarlsson/scheduler/boot/autoconfigure/DbSchedulerAutoConfiguration.java