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// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
export function normalizeEncoding(enc) {  if (enc == null || enc === "utf8" || enc === "utf-8") return "utf8";  return slowCases(enc);}
export function slowCases(enc) {  switch (enc.length) {    case 4:      if (enc === "UTF8") return "utf8";      if (enc === "ucs2" || enc === "UCS2") return "utf16le";      enc = `${enc}`.toLowerCase();      if (enc === "utf8") return "utf8";      if (enc === "ucs2") return "utf16le";      break;    case 3:      if (        enc === "hex" || enc === "HEX" ||        `${enc}`.toLowerCase() === "hex"      ) {        return "hex";      }      break;    case 5:      if (enc === "ascii") return "ascii";      if (enc === "ucs-2") return "utf16le";      if (enc === "UTF-8") return "utf8";      if (enc === "ASCII") return "ascii";      if (enc === "UCS-2") return "utf16le";      enc = `${enc}`.toLowerCase();      if (enc === "utf-8") return "utf8";      if (enc === "ascii") return "ascii";      if (enc === "ucs-2") return "utf16le";      break;    case 6:      if (enc === "base64") return "base64";      if (enc === "latin1" || enc === "binary") return "latin1";      if (enc === "BASE64") return "base64";      if (enc === "LATIN1" || enc === "BINARY") return "latin1";      enc = `${enc}`.toLowerCase();      if (enc === "base64") return "base64";      if (enc === "latin1" || enc === "binary") return "latin1";      break;    case 7:      if (        enc === "utf16le" || enc === "UTF16LE" ||        `${enc}`.toLowerCase() === "utf16le"      ) {        return "utf16le";      }      break;    case 8:      if (        enc === "utf-16le" || enc === "UTF-16LE" ||        `${enc}`.toLowerCase() === "utf-16le"      ) {        return "utf16le";      }      break;    case 9:      if (        enc === "base64url" || enc === "BASE64URL" ||        `${enc}`.toLowerCase() === "base64url"      ) {        return "base64url";      }      break;    default:      if (enc === "") return "utf8";  }}