# Path: munin/helper.py
# def roundrobin(*iterables):
#     "roundrobin('ABC', 'D', 'EF') --> A D E B F C"
#     # Recipe credited to George Sakkis
#     pending = len(iterables)
#     nexts = cycle(iter(it).__next__ for it in iterables)
#     while pending:
#         try:
#             for next in nexts:
#                 yield next()
#         except StopIteration:
#             pending -= 1
#             nexts = cycle(islice(nexts, pending))


from itertools import chain, islice
from collections import deque
from munin.helper import roundrobin
    from munin.testing import DummyDistanceFunction
    from munin.session import Session
import random
    import unittest
        next(bfs)
        for recom in bfs:
            yield recom
    else:
        # Create an iterator for each seed_song, in each associated rule:
        breadth_first_iters = deque()

        # Now populate the list of breadth first iterators:
        for left, right, *_ in associated:
            # The maximum number that a single seed_song in this rule may
            # deliver (at least 1 - himself, therefore the ceil)
            bulk = right if seed_song in left else left

            # We take the songs in the opposite set of the rule:
            for bulk_song in bulk:
                breadth_first = sorted_breadth_first_search(bulk_song)
                breadth_first_iters.append(breadth_first)

        # The result set will be build by half
        base_half = sorted_breadth_first_search(seed_song)
        try:
            next(base_half)
        except StopIteration:
            pass

        # Yield the base half first:
        songs_set = set([seed_song])

        # Now build the final result set by filling one half original songs,
        # and one half songs that were pointed to by rules.

# Path: munin/helper.py
# def roundrobin(*iterables):
#     "roundrobin('ABC', 'D', 'EF') --> A D E B F C"
#     # Recipe credited to George Sakkis
#     pending = len(iterables)
#     nexts = cycle(iter(it).__next__ for it in iterables)
#     while pending:
#         try:
#             for next in nexts:
#                 yield next()
#         except StopIteration:
#             pending -= 1
#             nexts = cycle(islice(nexts, pending))


# Path: munin/graph.py
from itertools import chain, islice
from collections import deque
from munin.helper import roundrobin
    from munin.testing import DummyDistanceFunction
    from munin.session import Session
import random
    import unittest

        next(bfs)
        for recom in bfs:
            yield recom
    else:
        # Create an iterator for each seed_song, in each associated rule:
        breadth_first_iters = deque()

        # Now populate the list of breadth first iterators:
        for left, right, *_ in associated:
            # The maximum number that a single seed_song in this rule may
            # deliver (at least 1 - himself, therefore the ceil)
            bulk = right if seed_song in left else left

            # We take the songs in the opposite set of the rule:
            for bulk_song in bulk:
                breadth_first = sorted_breadth_first_search(bulk_song)
                breadth_first_iters.append(breadth_first)

        # The result set will be build by half
        base_half = sorted_breadth_first_search(seed_song)
        try:
            next(base_half)
        except StopIteration:
            pass

        # Yield the base half first:
        songs_set = set([seed_song])

        # Now build the final result set by filling one half original songs,
        # and one half songs that were pointed to by rules.

        for recom in roundrobin(base_half, roundrobin(*breadth_first_iters)):