code: private void cleanDropins() {
          File dropinsDir = new File(serverConfigDir.getAbsolutePath(), "dropins");
          if (dropinsDir.exists()) {
              cleanDir(dropinsDir);
              log(MessageFormat.format(messages.getString("info.element.cleaned"), "dropins"));
          } else {
              log(MessageFormat.format(messages.getString("info.directory.noexist"), dropinsDir.getAbsolutePath()));
          }
      }
docs: Delete every file/folder in the serverConfigDir/dropins dir.