def METHOD_NAME(mock_tools, tmp_path):
    """If there's an existing managed WiX install, the validator succeeds."""
    # Mock the environment as if there is not WiX variable
    mock_tools.os.environ.get.return_value = None
    # Create a mock of a previously installed WiX version.
    wix_path = tmp_path / "tools" / "wix"
    wix_path.mkdir(parents=True)
    (wix_path / "heat.exe").touch()
    (wix_path / "light.exe").touch()
    (wix_path / "candle.exe").touch()
    wix = WiX.verify(mock_tools)
    # The environment was queried.
    mock_tools.os.environ.get.assert_called_with("WIX")
    # No download was attempted
    assert mock_tools.download.file.call_count == 0
    # The returned paths are as expected
    assert wix.heat_exe == tmp_path / "tools" / "wix" / "heat.exe"
    assert wix.light_exe == tmp_path / "tools" / "wix" / "light.exe"
    assert wix.candle_exe == tmp_path / "tools" / "wix" / "candle.exe"