code: public function load($files, $forceReload = false)
      {
          if (!is_array($files)) {
              // Make it an array so we can use the same code
              $files = [$files];
          }
  
          foreach ($files as $file) {
              if ((array_key_exists($file, $this->files) && !$forceReload)
                  || !is_file($file) || !is_readable($file)) {
                  // It's already loaded, or doesn't exist, so let's skip it
                  continue;
              }
  
              $ext = strtolower(pathinfo($file, PATHINFO_EXTENSION));
  
              if (!array_key_exists($ext, $this->readers)) {
                  throw new \Exception("No reader found for the extension '{$ext}'");
              }
  
              $conf = $this->readers[$ext]->read($file);
  
              if ($conf && is_array($conf)) {
                  // We're only interested if it is a non-empty array
                  $this->override($conf);
                  $this->files[$file] = true;
              }
  
              unset($conf);
          }
      }
docs: {@inheritdoc}