code: @Override
      public void execute() {
          if ((str == null || str.isEmpty()) && !FindContext.isAvailable()) {
              try {
                  str = editor.readLine("Find previous:");
                  editor.findPrevious(str);
                  FindContext.setLastSearch(str);
              } catch (IOException e) {
                  //noop
              }
          } else if (FindContext.isAvailable()) {
              editor.findPrevious(FindContext.getLastSearch());
          } else {
              editor.findPrevious(str);
              FindContext.setLastSearch(str);
          }
      }
docs: Executes the command.