pub fn normalize(s: &Str, form: &Str) -> Result<Str>Expand description
normalize: Unicode normalization. form must be "NFC"/"NFD"/"NFKC"/
"NFKD" (default "NFC"); any other value throws. A lone surrogate is
kept: it neither decomposes nor composes, so the text on each side of it
normalizes on its own.