docs: def get_all_clusters_sites():
      """Get all the cluster of all the sites.
  
      Returns:
          dict corresponding to the mapping cluster uid to python-grid5000 site
      """
      result = {}
      gk = get_api_client()
      sites = gk.sites.list()
      for site in sites:
          clusters = site.clusters.list()
          result.update({c.uid: site.uid for c in clusters})
      return result