public function decrementOffset()
    {
        $this->intOffset--;
        if (array_key_exists('file', $this->strTraceArray[$this->intOffset])) {
            $this->file = $this->strTraceArray[$this->intOffset]['file'];
        } else {
            $this->file = '';
        }
        if (array_key_exists('line', $this->strTraceArray[$this->intOffset])) {
            $this->line = $this->strTraceArray[$this->intOffset]['line'];
        } else {
            $this->line = '';
        }
    }