code: public static Class loadClass(String className, Class defaultValue) {
  	// OSGI env
  	Class clazz = _loadClass(new OSGiBasedClassLoading(), className, null, null);
  	if (clazz != null) return clazz;
  
  	// core classloader
  	clazz = _loadClass(new ClassLoaderBasedClassLoading(SystemUtil.getCoreClassLoader()), className, null, null);
  	if (clazz != null) return clazz;
  
  	// loader classloader
  	clazz = _loadClass(new ClassLoaderBasedClassLoading(SystemUtil.getLoaderClassLoader()), className, null, null);
  	if (clazz != null) return clazz;
  
  	return defaultValue;
      }
docs: loads a class from a String classname
  
  @param className
  @param defaultValue
  @return matching Class