code: function defaultGetCallingScript(offset = 0) {
  	const stack = (new Error).stack.split(/$/m);
  	const line = stack[(/^Error/).test(stack[0]) + 1 + offset];
  	const parts = line.split(/@(?![^/]*?\.xpi)|\(|\s+/g);
  	return parts[parts.length - 1].replace(/:\d+(?::\d+)?\)?$/, '');
  }
docs: the other values in `loadConfig` will be interpreted later 
  string parsers