public function test_escapeString()
 {
     $originalString = 'Via Tiepolo, 7';
     $expected = 'Via Tiepolo\\, 7';
     $this->assertEquals($expected, \XAPISdk\Util\StringUtil::escapeCharInString($originalString, ','));
 }
 protected function calculateQueryParamForKvpFilter(array $kvpFilter)
 {
     $res = '';
     $sep = '';
     foreach ($kvpFilter as $k => $v) {
         $k = StringUtil::escapeCharInString($k, self::PARAM_QUERY__FIELD_SEP);
         $k = StringUtil::escapeCharInString($k, self::PARAM_QUERY__FILTER_SEP);
         $v = urlencode($v);
         $v = StringUtil::escapeCharInString($v, self::PARAM_QUERY__FIELD_SEP);
         $v = StringUtil::escapeCharInString($v, self::PARAM_QUERY__FILTER_SEP);
         $res .= $sep . $k . self::PARAM_QUERY__FIELD_SEP . $v;
         $sep = self::PARAM_QUERY__FILTER_SEP;
     }
     return $res;
 }