Tries to guess extension for a mimetype.

    @param amimetype: name of a mimetype
    @time amimetype: string
    @return: the extension
    @rtype: string

def guess_extension(amimetype, normalize=False):
    """
    Tries to guess extension for a mimetype.

    @param amimetype: name of a mimetype
    @time amimetype: string
    @return: the extension
    @rtype: string
    """
    ext = _mimes.guess_extension(amimetype)
    if ext and normalize:
        # Normalize some common magic mis-interpreation
        ext = {'.asc': '.txt', '.obj': '.bin'}.get(ext, ext)
        from invenio.legacy.bibdocfile.api_normalizer import normalize_format
        return normalize_format(ext)
    return ext