502
502
heads = _find_possible_heads(parent_map, tip_keys, depth)
503
503
s, found_heads = _run_search(parent_map, heads, set(tip_keys))
504
_, start_keys, exclude_keys, key_count = s.get_result().get_recipe()
506
506
# Anything in found_heads are redundant start_keys, we hit them while
507
507
# walking, so we can exclude them from the start list.
508
508
start_keys = set(start_keys).difference(found_heads)