def normal(f, parentfiledata=None):
    """Mark a file normal and clean.

        parentfiledata: (mode, size, mtime) of the clean file

        parentfiledata should be computed from memory (for mode,
        size), as or close as possible from the point where we
        determined the file was clean, to limit the risk of the
        file having been changed by an external process between the
        moment where the file was determined to be clean and now."""
    pass
