def scan_in_memory(node, env, path=()):
    """
    "Scans" a Node.FS.Dir for its in-memory entries.
    """
    try:
        entries = node.entries
    except AttributeError:
        # It's not a Node.FS.Dir (or doesn't look enough like one for
        # our purposes), which can happen if a target list containing
        # mixed Node types (Dirs and Files, for example) has a Dir as
        # the first entry.
        return []
    entry_list = sorted(filter(do_not_scan, list(entries.keys())))
    return [entries[n] for n in entry_list]
"Scans" a Node.FS.Dir for its in-memory entries.