public function getEscapedString()
    {
        if ($this->escapedString === null) {
            $this->escapedString = str_replace('-', ' ', $this->escape($this->getRawString()));
            $this->escapedString = preg_replace(['/\s+([0-9])/','/\s+/'], ['$1', ' '], $this->escapedString);
        }
        return $this->escapedString;
    }