def METHOD_NAME(self, rel_path: str) -> str:
    from dlt.common.configuration.container import Container
    from dlt.common.pipeline import PipelineContext
    context = Container()[PipelineContext]
    if context.is_active():
        # pipeline is active, get the working directory
        return os.path.join(context.pipeline().working_dir, rel_path)
    return None