private function deriveExtensionMapping($name, array $extensions)
    {
        // Iterate through all of the extensions
        foreach($extensions as $extension)
        {
            // Check if it exists
            if(!isset($this->extensionMapping[$extension]))
            {
                // It doesn't, so initialize it
                $this->extensionMapping[$extension] = array();
            }

            // Add a mapping between the two
            $this->extensionMapping[$extension][] = $name;
        }
    }