async function loadJSON (file) {
		const xhr = new XMLHttpRequest();
		return new Promise(function (resolve) {
			xhr.overrideMimeType("application/json");
			xhr.open("GET", file, true);
			xhr.onreadystatechange = function () {
				if (xhr.readyState === 4 && xhr.status === 200) {
					// needs error handler try/catch at least
					let fileInfo = null;
					try {
						fileInfo = JSON.parse(xhr.responseText);
					} catch (exception) {
						// nothing here, but don't die
						Log.error(` loading json file =${file} failed`);
					}
					resolve(fileInfo);
				}
			};
			xhr.send(null);
		});
	}
Load a JSON file via XHR.
@param {string} file Path of the file we want to load.
@returns {Promise<object>} the translations in the specified file