Promise		async / await
.	function show_sketch_menu(tab) {		async function show_sketch_menu(tab) {
			try {
	// https://github.com/mdn/webextensions-examples/blob/master/context-menu-copy-link-with-types/background.js		// https://github.com/mdn/webextensions-examples/blob/master/context-menu-copy-link-with-types/background.js
.	let loaded_first = false;		const result = await browser.tabs.executeScript(tab.id, {
	browser.tabs.executeScript(tab.id, {
	code: "typeof SketchSwitch === 'function'",		code: "typeof SketchSwitch === 'function'",
.	}).then(result => {		});
	if (!result || result[0] !== true) {    // SketchSwitch is not defined		if (!result || result[0] !== true) {    // SketchSwitch is not defined
.	loaded_first = true;
	// for malformed URI --- SketchSwitch.Utils.convertStringEncoding()		// for malformed URI --- SketchSwitch.Utils.convertStringEncoding()
.	return browser.tabs.executeScript(tab.id, {		await browser.tabs.executeScript(tab.id, {
	code: `		code: `
	original__decodeURIComponent = decodeURIComponent;		original__decodeURIComponent = decodeURIComponent;
	decodeURIComponent = s => unescape(s);		decodeURIComponent = s => unescape(s);
	true;   // Script '<anonymous code>' result is non-structured-clonable data		true;   // Script '<anonymous code>' result is non-structured-clonable data
	`,		`,
	});		});
.	}		await browser.tabs.executeScript(tab.id, {
	}).then(result => {
	if (loaded_first) {
	return browser.tabs.executeScript(tab.id, {
	file: "/content/SketchSwitch.js",		file: "/content/SketchSwitch.js",
	});		});
.	}		await browser.tabs.executeScript(tab.id, {
	}).then(_ => {
	if (loaded_first) {
	return browser.tabs.executeScript(tab.id, {
	code: `		code: `
	decodeURIComponent = original__decodeURIComponent;		decodeURIComponent = original__decodeURIComponent;
	true;		true;
	`,		`,
	});		});
.	}		await browser.tabs.executeScript(tab.id, {
	}).then(_ => {
	if (loaded_first) {
	return browser.tabs.executeScript(tab.id, {
	file: "/content/sketch-patch.js",		file: "/content/sketch-patch.js",
	});		});
	}		}
.	}).then(_ => {		await browser.tabs.executeScript(tab.id, {
	return browser.tabs.executeScript(tab.id, {
	code: `		code: `
	(_ => {		(_ => {
	const canvas = document.getElementById("__sketch_switch_canvas__");		const canvas = document.getElementById("__sketch_switch_canvas__");
	if (canvas) {		if (canvas) {
	// Sketch Menu is shown.		// Sketch Menu is shown.
	return;		return;
	}		}
	const sketch = new SketchSwitch(window, {});		const sketch = new SketchSwitch(window, {});
	sketch.show();		sketch.show();
	})();		})();
	`,		`,
	});		});
.	}).catch(error => {		} catch(error) {
	console.error(error.message || error);		console.error(error.message || error);
	console.dir(error);		console.dir(error);
.	});		}
	}		}