src/vs/workbench/api/common/extHostWindow.ts/ExtHostWindow/openUri
class ExtHostWindow:	openUri(stringOrUri: string | URI, options: IOpenUriOptions): Promise<boolean> {
		let uriAsString: string | undefined;
		if (typeof stringOrUri === 'string') {
			uriAsString = stringOrUri;
			try {
				stringOrUri = URI.parse(stringOrUri);
			} catch (e) {
				return Promise.reject(`Invalid uri - '${stringOrUri}'`);
			}
		}
		if (isFalsyOrWhitespace(stringOrUri.scheme)) {
			return Promise.reject('Invalid scheme - cannot be empty');
		} else if (stringOrUri.scheme === Schemas.command) {
			return Promise.reject(`Invalid scheme '${stringOrUri.scheme}'`);
		}
		return this._proxy.$openUri(stringOrUri, uriAsString, options);
	}