private static String readFile(String filename) throws IOException {
    BufferedReader br = new BufferedReader(new FileReader(filename));
    String nextLine = "";
    StringBuilder sb = new StringBuilder();
    while ((nextLine = br.readLine()) != null) {
      sb.append(nextLine);
    }
    return sb.toString();
  }
This test case is to test the following test scenarios: 1) Behaviour of Transaction Manager in
multithreaded transactions. We will have around five threads doing different activities. The
response to those activities by transaction manager is tested.
geode-core/src/distributedTest/java/org/apache/geode/internal/jta/dunit/TxnManagerMultiThreadDUnitTest.java