code: private function registerAutoload() {
          spl_autoload_register(function ($classname) {
              try {
                  foreach (self::$_imported as $dir => $flag) {
                      $file = $dir . DIRECTORY_SEPARATOR .
                          \str_replace("\\", DIRECTORY_SEPARATOR, $classname) . ".php";
                      if (file_exists($file)) {
                          include $file;
                      }
                  }
              } catch (\Throwable $exc) {
                  error_log($exc->getMessage());
                  error_log($exc->getCode());
                  error_log($exc->getTraceAsString());
                  return false;
              }
              if (class_exists($classname) || interface_exists($classname) ||
                  trait_exists($classname)) {
                  return true;
              }
              return false;
          });
      }
docs: 注册自动载入