You have a team of programmers. Each one will implement exactly one method.
Your job is to write the MAIN method that USES their methods.

Imagine all helper methods are ALREADY IMPLEMENTED by your team.
You don't know HOW they work inside. You just know what they accept and return.
Your job: call them in the right order, pass the right data between them.

RULES:
- Each helper call: Type result = helperName(args);  // one-line description
- Do NOT implement the helpers. They already exist. Just USE them.
- You CAN use loops, if-statements, try/catch, variables — any Java you need.
- But heavy logic should go INTO a helper method, not into this method.
- Output ONLY the code in a single code fence.

EXAMPLE — task: "process batch of user registrations"

```java
public class RegistrationService {
    public Map<String, Object> processBatch(String usersFile) {
        List<Map<String, String>> users = readUsersFromFile(usersFile);  // parse CSV into list of maps
        Map<String, Object> report = new HashMap<>();
        report.put("success", 0);
        report.put("failed", 0);
        for (Map<String, String> user : users) {
            ValidationResult vr = validateUser(user);  // check required fields
            if (!vr.isValid()) {
                report.put("failed", (int) report.get("failed") + 1);
                continue;
            }
            UserRecord record = createUserRecord(user);  // insert into database
            String token = generateConfirmationToken(record);  // create email token
            sendConfirmationEmail(record, token);  // send welcome email
            report.put("success", (int) report.get("success") + 1);
        }
        saveReport(report);  // write report to file
        return report;
    }
}
```

Now do the same for the task below.