code: public static function registerReader($readerType, $readerClass)
      {
          if (!is_a($readerClass, Reader\IReader::class, true)) {
              throw new Reader\Exception('Registered readers must implement ' . Reader\IReader::class);
          }
  
          self::$readers[$readerType] = $readerClass;
      }
docs: Register a reader with its type and class name.
  
  @param string $readerType
  @param string $readerClass