def METHOD_NAME(mock_api_response, source):
    """
    Checks if get_response method returnes DataFrame for each of the 4 possible sources.
    Test assert that the mock was called exactly once.
    Args:
        mock_api_response: Mocked return_value for get_response method.
        source: The endpoint source to be accessed.
    """
    query = vc.get_response(source=source, to_date="2023-03-24", from_date="2023-03-24")
    assert isinstance(query, pd.DataFrame)
    mock_api_response.assert_called_once()