def _make_block_conf(block):
    """Returns a list of .config strings for a block (list) of items."""

    # Collect the substrings in a list and later use join() instead of += to
    # build the final .config contents. With older Python versions, this yields
    # linear instead of quadratic complexity.
    strings = []
    for item in block:
        strings.extend(item._make_conf())
    return strings