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/** * CREDIT: https://gist.github.com/enepomnyaschih/72c423f727d395eeaa09697058238727 * Encodes a given Uint8Array, ArrayBuffer or string into RFC4648 base64 representation * @param data */export function encode(data: ArrayBuffer | string): string {  const uint8 = typeof data === "string"    ? new TextEncoder().encode(data)    : data instanceof Uint8Array    ? data    : new Uint8Array(data);  let result = "",    i;  const l = uint8.length;  for (i = 2; i < l; i += 3) {    result += base64abc[uint8[i - 2] >> 2];    result += base64abc[((uint8[i - 2] & 0x03) << 4) | (uint8[i - 1] >> 4)];    result += base64abc[((uint8[i - 1] & 0x0f) << 2) | (uint8[i] >> 6)];    result += base64abc[uint8[i] & 0x3f];  }  if (i === l + 1) {    // 1 octet yet to write    result += base64abc[uint8[i - 2] >> 2];    result += base64abc[(uint8[i - 2] & 0x03) << 4];    result += "==";  }  if (i === l) {    // 2 octets yet to write    result += base64abc[uint8[i - 2] >> 2];    result += base64abc[((uint8[i - 2] & 0x03) << 4) | (uint8[i - 1] >> 4)];    result += base64abc[(uint8[i - 1] & 0x0f) << 2];    result += "=";  }  return result;}
/** * CREDIT: https://gist.github.com/enepomnyaschih/72c423f727d395eeaa09697058238727 * Decodes RFC4648 base64 string into an Uint8Array * @param data */export function decode(data: string): Uint8Array {  if (data.length % 4 !== 0) {    throw new Error("Unable to parse base64 string.");  }  const index = data.indexOf("=");  if (index !== -1 && index < data.length - 2) {    throw new Error("Unable to parse base64 string.");  }  let missingOctets = data.endsWith("==") ? 2 : data.endsWith("=") ? 1 : 0,    n = data.length,    result = new Uint8Array(3 * (n / 4)),    buffer;  for (let i = 0, j = 0; i < n; i += 4, j += 3) {    buffer = getBase64Code(data.charCodeAt(i)) << 18 |      getBase64Code(data.charCodeAt(i + 1)) << 12 |      getBase64Code(data.charCodeAt(i + 2)) << 6 |      getBase64Code(data.charCodeAt(i + 3));    result[j] = buffer >> 16;    result[j + 1] = (buffer >> 8) & 0xFF;    result[j + 2] = buffer & 0xFF;  }  return result.subarray(0, result.length - missingOctets);}
/** * CREDIT: https://gist.github.com/enepomnyaschih/72c423f727d395eeaa09697058238727 * @param charCode */function getBase64Code(charCode: number): number {  if (charCode >= base64codes.length) {    throw new Error("Unable to parse base64 string.");  }  const code = base64codes[charCode];  if (code === 255) {    throw new Error("Unable to parse base64 string.");  }  return code;}
// Copyright 2018-2021 the Deno authors. All rights reserved. MIT license.const base64abc = [  "A",  "B",  "C",  "D",  "E",  "F",  "G",  "H",  "I",  "J",  "K",  "L",  "M",  "N",  "O",  "P",  "Q",  "R",  "S",  "T",  "U",  "V",  "W",  "X",  "Y",  "Z",  "a",  "b",  "c",  "d",  "e",  "f",  "g",  "h",  "i",  "j",  "k",  "l",  "m",  "n",  "o",  "p",  "q",  "r",  "s",  "t",  "u",  "v",  "w",  "x",  "y",  "z",  "0",  "1",  "2",  "3",  "4",  "5",  "6",  "7",  "8",  "9",  "+",  "/",];
// CREDIT: https://gist.github.com/enepomnyaschih/72c423f727d395eeaa09697058238727const base64codes = [  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  255,  62,  255,  255,  255,  63,  52,  53,  54,  55,  56,  57,  58,  59,  60,  61,  255,  255,  255,  0,  255,  255,  255,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9,  10,  11,  12,  13,  14,  15,  16,  17,  18,  19,  20,  21,  22,  23,  24,  25,  255,  255,  255,  255,  255,  255,  26,  27,  28,  29,  30,  31,  32,  33,  34,  35,  36,  37,  38,  39,  40,  41,  42,  43,  44,  45,  46,  47,  48,  49,  50,  51,];