/**
  * @param string $input
  * @return string
  */
 private function processDocument($fixturePath, $input)
 {
     PHPFIT_Fixture::setHtmlRenderer(new PHPFIT_HtmlRenderer_Fitnesse());
     $fixture = new PHPFIT_Fixture($fixturePath);
     try {
         $tables = PHPFIT_Parse::create($input);
         $fixture->doTables($tables);
     } catch (PHPFIT_Exception_Parse $e) {
         $tables = $this->exception($e, $fixture);
     }
     $this->counts = $fixture->counts;
     $this->totalCounts->tally($fixture->counts);
     return $tables->toString();
 }