code: public static function parseJson($json, $file = null)
      {
          if (null === $json) {
              return;
          }
          $data = json_decode($json, true);
          if (null === $data && JSON_ERROR_NONE !== json_last_error()) {
              self::validateSyntax($json, $file);
          }
  
          return $data;
      }
docs: Parses json string and returns hash.
  
  @param string $json json string
  @param string $file the json file
  
  @return mixed