#bael-3314-new:Update JMockit articles (#14355)

* #bael-3314-new:remove unused method

* #bael-3314-new:change private to protected

testing-modules/mocks/src/main/java/com/baeldung/jmockit/AdvancedCollaborator.java

@@ -7,7 +7,7 @@ public class AdvancedCollaborator {
     public AdvancedCollaborator(String string) throws Exception{
         i = string.length();
     }
-    public String methodThatCallsPrivateMethod(int i){
+    public String methodThatCallsProtectedMethod(int i){
         return protectedMethod() + i;
     }
     public int methodThatReturnsThePrivateField(){

testing-modules/mocks/src/main/java/com/baeldung/jmockit/AppManager.java

@@ -20,7 +20,4 @@ public class AppManager {
         return new Random().nextInt(7);
     }
 
-    private static Integer stringToInteger(String num) {
-        return Integer.parseInt(num);
-    }
 }

testing-modules/mocks/src/test/java/com/baeldung/jmockit/AdvancedCollaboratorIntegrationTest.java

@@ -31,7 +31,7 @@ public class AdvancedCollaboratorIntegrationTest {
                 return "mocked: ";
             }
         };
-        String res = mock.methodThatCallsPrivateMethod(1);
+        String res = mock.methodThatCallsProtectedMethod(1);
         assertEquals("mocked: 1", res);
     }