// Create execution data file:
    File execfile = new File(folder.getRoot(), "test.exec");
    OutputStream out = new FileOutputStream(execfile);
    ExecutionDataWriter writer = new ExecutionDataWriter(out);
    writer.visitSessionInfo(new SessionInfo("id", 1, 2));
    writer.visitClassExecution(new ExecutionData(123, "MyClass", 15));
    out.close();
    final CoverageSession session = new CoverageSession("Description",
        Arrays.asList(root1), Path.fromOSString(execfile.getAbsolutePath()),
        configuration);