to_taskflow

def make_variable_collector_task(
        name: str,
        input_rebinds: List[str],
        provides: str,
    ):
    """ Create an intermedidate "collector" task to rebind multiple
    connections to a single output.
    """
    class MultiConnectionCollector(task.Task):
        """
        This task gets automatically inserted before any input defined
        as 'allow_multi_connection'.
        In taskflow, an input can only be rebind to a single value,
        so this task collects multiple inputs into a single list output.
        """
        def execute(self, **kwargs):
            # node input is connected to only 1 output, leave it as-is.
            if len(kwargs) == 1:
                return kwargs[list(kwargs.keys())[0]]

            # force a rebind of the depending node outputs and
            # provide the result as a list to the following node input.
            return [kwargs[key] for key in kwargs.keys()]

    return MultiConnectionCollector(
        name=name,
        rebind=input_rebinds,
        provides=provides
    )