Prevent instantiating utility classes

src/main/java/wtf/beatrice/hidekobot/util/CommandUtil.java

@@ -27,6 +27,10 @@ public class CommandUtil
 
     private static final Logger LOGGER = LoggerFactory.getLogger(CommandUtil.class);
 
+    private CommandUtil() {
+        throw new IllegalStateException("Utility class");
+    }
+
     /**
      * Function to delete a message when a user clicks the "delete" button attached to that message.
      * This will check in the database if that user ran the command originally.

src/main/java/wtf/beatrice/hidekobot/util/FormatUtil.java

@@ -12,6 +12,9 @@ import java.util.Arrays;
 public class FormatUtil
 {
 
+    private FormatUtil() {
+        throw new IllegalStateException("Utility class");
+    }
 
     // cosmetic string to print on startup.
     private static final String LOGO = """

src/main/java/wtf/beatrice/hidekobot/util/RandomUtil.java

@@ -10,6 +10,10 @@ import java.util.Random;
 public class RandomUtil
 {
 
+    private RandomUtil() {
+        throw new IllegalStateException("Utility class");
+    }
+
     // the Random instance that we should always use when looking for an RNG based thing.
     // the seed is updated periodically, if the random.org integration is enabled.
     private static Random randomInstance = new SecureRandom();

src/main/java/wtf/beatrice/hidekobot/util/SerializationUtil.java

@@ -10,6 +10,10 @@ import java.util.List;
 public class SerializationUtil
 {
 
+    private SerializationUtil() {
+        throw new IllegalStateException("Utility class");
+    }
+
     public static <T> String serializeBase64(List<T> dataList) {
 
         try (ByteArrayOutputStream bo = new ByteArrayOutputStream();