Extract a Random instance to a variable (#1942)

core-java/src/main/java/com/baeldung/string/StringHelper.java

@@ -2,23 +2,23 @@ package com.baeldung.string;
 
 import java.util.Optional;
 
-public class StringHelper {
-    public static String removeLastChar(String s) {
+class StringHelper {
+    static String removeLastChar(String s) {
         return (s == null || s.length() == 0) ? s : (s.substring(0, s.length() - 1));
     }
 
-    public static String removeLastCharRegex(String s) {
+    static String removeLastCharRegex(String s) {
         return (s == null) ? s : s.replaceAll(".$", "");
     }
 
-    public static String removeLastCharOptional(String s) {
+    static String removeLastCharOptional(String s) {
         return Optional.ofNullable(s)
             .filter(str -> str.length() != 0)
             .map(str -> str.substring(0, str.length() - 1))
             .orElse(s);
     }
 
-    public static String removeLastCharRegexOptional(String s) {
+    static String removeLastCharRegexOptional(String s) {
         return Optional.ofNullable(s)
             .map(str -> str.replaceAll(".$", ""))
             .orElse(s);