def METHOD_NAME():
    # For all Unicode characters, see whether they have case conversions
    # Return 2 sets: one of simple symmetric conversion cases and another
    # with complex cases.
    complexes = []
    symmetrics = []
    for ch in range(sys.maxunicode + 1):
        if ch >= 0xd800 and ch <= 0xDBFF:
            continue
        if ch >= 0xdc00 and ch <= 0xDFFF:
            continue
        uch = chr(ch)
        fold = uch.casefold()
        upper = uch.upper()
        lower = uch.lower()
        symmetric = False
        if uch != upper and len(upper) == 1 and uch == lower and uch == fold:
            lowerUpper = upper.lower()
            foldUpper = upper.casefold()
            if lowerUpper == foldUpper and lowerUpper == uch:
                symmetric = True
                symmetrics.append((ch, ord(upper), ch - ord(upper)))
        if uch != lower and len(lower) == 1 and uch == upper and lower == fold:
            upperLower = lower.upper()
            if upperLower == uch:
                symmetric = True
        if fold == uch:
            fold = ""
        if upper == uch:
            upper = ""
        if lower == uch:
            lower = ""
        if (fold or upper or lower) and not symmetric:
            complexes.append((uch, fold, upper, lower))
    return symmetrics, complexes