docs: def _get_index_servers(self):
          """Gets index-servers current configured in pypirc."""
          idx_srvs = []
          if 'index-servers' in self.conf.options('distutils'):
              idx = self.conf.get('distutils', 'index-servers')
              idx_srvs = [srv.strip() for srv in idx.split('\n') if srv.strip()]
          return idx_srvs