code: public function start()
      {
          if ($this->isRunning()) {
              return;
          }
  
          $this->data["realmem_start"] = memory_get_usage(true);
          $this->data["emalloc_start"] = memory_get_usage();
  
          $this->started = microtime(true);
          $this->running = true;
      }
docs: Starts the timer.
  
  @return void