Comment 8 for bug 1730730

Reviewed: https://review.openstack.org/516782
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=ea63b3b40f0abddce22a02f79ff9275d55d37407
Submitter: Zuul
Branch: master

commit ea63b3b40f0abddce22a02f79ff9275d55d37407
Author: Jay Pipes <email address hidden>
Date: Tue Oct 31 16:03:33 2017 -0400

    finish refactor AllocCandidates._get_by_filters()

    This patch completes the refactoring of the
    AllocationCandidates._get_by_filters() mega-method by splitting out the
    remaining pieces of code that handle the construction of the
    part-shared, part-non-shared allocation requests for when there are
    sharing providers in a deployment.

    The split-out _alloc_candidates_with_shared() is still a long, complex
    method and I'll continue trying to reduce the complexity there and break
    functions out of it further. I did uncomplicate a part of the function
    with use of the itertools.product() function to replace a faulty use of
    zip() against a list of allocation request resource lists.

    Closes-Bug: #1730730
    Change-Id: Ibcfd1a28f36d3c7ccd26fcc6386207e4a25300d4