Fix detailed error checkstyle

Author: kvz

example/src/main/java/io/tus/java/example/Api2DevdockTusDetailedError.java

@@ -15,6 +15,12 @@
 import java.util.Map;
 
 public final class Api2DevdockTusDetailedError {
+    /**
+     * Run the API2 devdock detailed-error scenario.
+     *
+     * @param args Unused command-line arguments.
+     * @throws Exception Thrown when the scenario cannot be executed.
+     */
     public static void main(String[] args) throws Exception {
         final JSONObject scenario = Api2DevdockScenario.loadScenario();
         final JSONObject result = uploadExpectingDetailedError(

src/main/java/io/tus/java/client/TusClient.java

@@ -465,6 +465,18 @@ public HttpURLConnection terminateUpload(@NotNull URL uploadURL)
         return connection;
     }
 
+    /**
+     * Opens the HTTP connection used by this client.
+     *
+     * <p>Subclasses may override this method to provide a custom transport for tests or specialized
+     * environments. Implementations should return a fresh {@link HttpURLConnection} for the given
+     * URL and must not connect it; callers configure headers, method, and hooks after this method
+     * returns.
+     *
+     * @param uploadURL The request URL.
+     * @return A new, unconnected HTTP connection.
+     * @throws IOException Thrown if a connection cannot be opened.
+     */
     @NotNull
     protected HttpURLConnection openConnection(@NotNull URL uploadURL) throws IOException {
         if (proxy != null) {

src/main/java/io/tus/java/client/TusRequestException.java

@@ -6,7 +6,7 @@
 /**
  * An {@link IOException} with TUS request context.
  */
-public class TusRequestException extends IOException implements TusDetailedError {
+public final class TusRequestException extends IOException implements TusDetailedError {
     private final TusRequestSnapshot snapshot;
 
     TusRequestException(String message, TusRequestSnapshot snapshot, IOException cause) {

src/main/java/io/tus/java/client/TusResponseException.java

@@ -6,7 +6,7 @@
 /**
  * A {@link ProtocolException} with TUS request and response context.
  */
-public class TusResponseException extends ProtocolException implements TusDetailedError {
+public final class TusResponseException extends ProtocolException implements TusDetailedError {
     private final String responseBody;
     private final int responseStatus;
     private final TusRequestSnapshot snapshot;