code: private ClassLoader getParentClassLoader() throws GuacamoleException {
  
          // Retrieve lib directory
          File libDir = new File(environment.getGuacamoleHome(), LIB_DIRECTORY);
  
          // If lib directory does not exist, use default class loader
          if (!libDir.isDirectory())
              return ExtensionModule.class.getClassLoader();
  
          // Return classloader which loads classes from all .jars within the lib directory
          return DirectoryClassLoader.getInstance(libDir);
  
      }
docs: Returns the classloader that should be used as the parent classloader
  for all extensions. If the GUACAMOLE_HOME/lib directory exists, this
  will be a classloader that loads classes from within the .jar files in
  that directory. Lacking the GUACAMOLE_HOME/lib directory, this will
  simply be the classloader associated with the ExtensionModule class.
  
  @return
  The classloader that should be used as the parent classloader for
  all extensions.
  
  @throws GuacamoleException
  If an error occurs while retrieving the classloader.