code: def test_connections_path_none_value(self, mock_hvac):
      mock_client = mock.MagicMock()
      mock_hvac.Client.return_value = mock_client
  
      kwargs = {
          "connections_path": None,
          "mount_point": "airflow",
          "auth_type": "token",
          "url": "http://127.0.0.1:8200",
          "token": "s.FnL7qg0YnHZDpf4zKKuFy0UK",
      }
  
      test_client = VaultBackend(**kwargs)
      assert test_client.get_conn_uri(conn_id="test") is None
      mock_hvac.Client.assert_not_called()
  
imports: from __future__ import annotations
  from unittest import mock
  import pytest
  from hvac.exceptions import InvalidPath, VaultError
  from airflow.providers.hashicorp.secrets.vault import VaultBackend
label_desc: Use image node_id 16 for calling the TestVaultSecrets obj's underlying member method code with example usage: obj.test_connections_path_none_value(mock_hvac) without return types