def get_item_hrefs(result_collection):
    """
    Given a result_collection (returned by a previous API call that
    returns a collection, like get_bundle_list() or search()), return a
    list of item hrefs.

    'result_collection' a JSON object returned by a previous API
    call.

    Returns a list, which may be empty if no items were found.
    """

    # Argument error checking.
    assert result_collection is not None

    result = []

    links = result_collection.get('_links')
    if links is not None:
        items = links.get('items')
        if items is not None:
            for item in items:
                result.append(item.get('href'))

    return result