code: def get_url(pif, dataset, version=1, site="https://citrination.com"):
      
      return "{site}/datasets/{dataset}/version/{version}/pif/{uid}".format(
          uid=pif.uid, version=version, dataset=dataset, site=site
      )
docs: Construct the URL of a PIF on a site
      :param pif: to construct URL for
      :param dataset: the pif will belong to
      :param version: of the PIF (default: 1)
      :param site: for the dataset (default: https://citrination.com)
      :return: the URL as a string