src/vs/workbench/services/keybinding/common/macLinuxKeyboardMapper.ts/ScanCodeCombo/getProducedChar
class ScanCodeCombo:	public getProducedChar(mapping: IMacLinuxKeyMapping): string {
		const charCode = MacLinuxKeyboardMapper.getCharCode(this.getProducedCharCode(mapping));
		if (charCode === 0) {
			return ' --- ';
		}
		if (charCode >= CharCode.U_Combining_Grave_Accent && charCode <= CharCode.U_Combining_Latin_Small_Letter_X) {
			// combining
			return 'U+' + charCode.toString(16);
		}
		return '  ' + String.fromCharCode(charCode) + '  ';
	}