[Demonstration 1]

[Buggy Method]
private void load() {
    // Clear map before adding data
    this.messages = new HashMap<>();
    for (Map.Entry entry : this.getLocaleFile().getAll().entrySet()) {
        String key = (String) entry.getKey();
        String value = (String) entry.getValue();
        getMessages().put(key, value);
    }
}

[Buggy Hunk]
String value = (String) entry.getValue();

[Patch]
String value = String.valueOf(entry.getValue());

[Demonstration 2]

[Buggy Method]
public void clearMeta(String value, CommandSender sender) {
    getCalculable().getMeta().remove(value);
    sender.sendMessage(format("Meta for " + calc.getName() + " " + getCalculable().getName() + " - cleared"));
}

[Buggy Hunk]
getCalculable().getMeta().remove(value);

[Patch]
getCalculable().removeValue(value);

[Demonstration 3]

[Buggy Method]
private static File downloadFilterFile(File dest, int filterId, String filterDownloadUrl, String fileName) throws IOException {
    log.debug("Start download filter " + filterId + " from " + filterDownloadUrl);
    String downloadUrl = String.format(filterDownloadUrl, filterId);
    String response = UrlUtils.downloadString(new URL(downloadUrl), "UTF-8");
    File filterFile = new File(dest, fileName);
    FileUtils.write(filterFile, response);
    log.debug("Filter " + filterId + " download successfully");
    return filterFile;
}

[Buggy Hunk]
FileUtils.write(filterFile, response);

[Patch]
FileUtils.write(filterFile, response, "utf-8");