original_string: public function start_html() {
          if ($this->bar) {
              throw new \coding_exception('Already started');
          }
          $this->bar = new \progress_bar();
          $this->bar->create();
          echo \html_writer::start_div('wibbler');
      }
code: public function start_html() {
          if ($this->bar) {
              throw new \coding_exception('Already started');
          }
          $this->bar = new \progress_bar();
          $this->bar->create();
          echo \html_writer::start_div('wibbler');
      }
code_tokens: public function start_html ( ) { if ( $ this -> bar ) { throw new \ coding_exception ( 'Already started' ) ; } $ this -> bar = new \ progress_bar ( ) ; $ this -> bar -> create ( ) ; echo \ html_writer :: start_div ( 'wibbler' ) ; }
docstring: Starts to output progress.
  
  Called in constructor and in update_progress if required.
  
  @throws \coding_exception If already started
docstring_tokens: Starts to output progress .