h.Del(headerName)
	}
	for _, prefix := range extraHeaderPrefixes.Value() {
		for k := range h {
			if hasPrefixIgnoreCase(k, prefix) {
				delete(h, k) // we have the raw key so avoid relying on canonicalization
			}
		}
	}
}

func hasPrefixIgnoreCase(s, prefix string) bool {
	return len(s) >= len(prefix) && strings.EqualFold(s[:len(prefix)], prefix)
}