src/vs/workbench/contrib/snippets/browser/insertSnippet.ts/Args/fromUser
class Args:	static fromUser(arg: any): Args {
		if (!arg || typeof arg !== 'object') {
			return Args._empty;
		}
		let { snippet, name, langId } = arg;
		if (typeof snippet !== 'string') {
			snippet = undefined;
		}
		if (typeof name !== 'string') {
			name = undefined;
		}
		if (typeof langId !== 'string') {
			langId = undefined;
		}
		return new Args(snippet, name, langId);
	}