Refactoring creation of the lesson moving it towards the plugin

src/main/java/org/owasp/webgoat/plugins/Plugin.java

@@ -124,9 +124,12 @@ public class Plugin {
         }
     }
 
-
-    public Class<AbstractLesson> getLesson() {
-        return lesson;
+    public AbstractLesson getLesson() {
+        try {
+            return lesson.newInstance();
+        } catch (IllegalAccessException | InstantiationException e) {
+            throw new PluginLoadingFailure("Unable to instantiate the lesson " + lesson.getName(), e);
+        }
     }
 
     public Optional<File> getLessonSolution(String language) {

src/main/java/org/owasp/webgoat/plugins/PluginClassLoader.java

@@ -1,15 +1,21 @@
 package org.owasp.webgoat.plugins;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 public class PluginClassLoader extends ClassLoader {
 
+    private final Logger logger = LoggerFactory.getLogger(Plugin.class);
     private final byte[] classFile;
 
-    public PluginClassLoader(ClassLoader parent, byte[] classFile) {
+    public PluginClassLoader(ClassLoader parent, String nameOfClass, byte[] classFile) {
         super(parent);
+        logger.debug("Creating class loader for {}", nameOfClass);
         this.classFile = classFile;
     }
 
     public Class findClass(String name) {
+        logger.debug("Finding class " + name);
         return defineClass(name, classFile, 0, classFile.length);
     }