How to use the maup.assign.assign_to_max function in maup

def absorb_by_shared_perimeter(sources, targets, relative_threshold=None):
    if len(sources) == 0:
        return targets

    if len(targets) == 0:
        raise IndexError("targets must be nonempty")

    inters = intersections(sources, targets, area_cutoff=None).buffer(0)
    assignment = assign_to_max(inters.length)

    if relative_threshold is not None:
        under_threshold = (
            sources.area / assignment.map(targets.area)
        ) < relative_threshold
        assignment = assignment[under_threshold]

    sources_to_absorb = GeoSeries(
        sources.groupby(assignment).apply(unary_union), crs=sources.crs,
    )

    result = targets.union(sources_to_absorb)

    # The .union call only returns the targets who had a corresponding
    # source to absorb. Now we fill in all of the unchanged targets.
    result = result.reindex(targets.index)