Flarum\Extension\Extension::setVersion PHP Method

    public function setVersion($version)
    {
        $this->version = $version;
        return $this;
    }

 /**
  * @return Collection
  */
 public function getExtensions()
 {
     $extensionsDir = $this->getExtensionsDir();
     $dirs = array_diff(scandir($extensionsDir), ['.', '..']);
     $extensions = new Collection();
     $installed = json_decode(file_get_contents(public_path('vendor/composer/installed.json')), true);
     foreach ($dirs as $dir) {
         if (file_exists($manifest = $extensionsDir . '/' . $dir . '/composer.json')) {
             $extension = new Extension($extensionsDir . '/' . $dir, json_decode(file_get_contents($manifest), true));
             if (empty($extension->name)) {
                 continue;
             }
             foreach ($installed as $package) {
                 if ($package['name'] === $extension->name) {
                     $extension->setInstalled(true);
                     $extension->setVersion($package['version']);
                     $extension->setEnabled($this->isEnabled($dir));
                 }
             }
             $extensions->put($dir, $extension);
         }
     }
     return $extensions->sortBy(function ($extension, $name) {
         return $extension->composerJsonAttribute('extra.flarum-extension.title');
     });
 }