converse-built/node_modules/fast-text-encoding/externs.js

/**
 * @constructor
 */
var Buffer;

/**
 * @param {!ArrayBuffer} raw
 * @param {number} byteOffset
 * @param {number} byteLength
 * @return {!Buffer}
 */
Buffer.from = function(raw, byteOffset, byteLength) {};

/**
 * @this {*}
 * @param {string} encoding
 * @return {string}
 */
Buffer.prototype.toString = function(encoding) {};