protected function getCaller(Frame $frame)
    {
        $class = $frame->getClass();
        $fn = $frame->getFunction();
        $caller = '';

        if ($class) {
            $caller .= $class;
        }

        if ($class && $fn) {
            $caller .= '::';
        }

        if ($fn) {
            $caller .= $fn . '(' . $this->getArgumentsAsString($frame->getArgs()) . ')';
        }

        return $caller;
    }