TransactionContextFuture beginTransaction()

in cloud-spanner-r2dbc/src/main/java/com/google/cloud/spanner/r2dbc/v2/DatabaseClientTransactionManager.java [79:86]


  TransactionContextFuture beginTransaction() {
    if (this.isInTransaction()) {
      throw new TransactionInProgressException(this.isInReadWriteTransaction());
    }
    this.transactionManager = this.dbClient.transactionManagerAsync();
    this.txnContextFuture = this.transactionManager.beginAsync();
    return this.txnContextFuture;
  }