code: @Override
      public void refresh() {
          // do nothing
          org.grails.io.support.Resource descriptor = getDescriptor();
          if (grailsApplication == null || descriptor == null) {
              return;
          }
  
          ClassLoader parent = grailsApplication.getClassLoader();
          GroovyClassLoader gcl = new GroovyClassLoader(parent);
          try {
              initialisePlugin(gcl.parseClass(descriptor.getFile()));
          } catch (Exception e) {
              LOG.error("Error refreshing plugin: " + e.getMessage(), e);
          }
      }
docs: /* (non-Javadoc)
  @see org.grails.plugins.AbstractGrailsPlugin#refresh()