code: protected function prepareTemplate($templateTxt)
      {
          $patterns = [
              '/\\\{%(.*)%\\\}/U', // 1 Replace all {%Var%}...
              '/\s+/',             // 2 Replace all white-spaces...
          ];
  
          $replacements = [
              '(?<$1>.*)',         // 1 ...with (?<Var>.*)
              ' ',                 // 2 ...with a single space
          ];
  
          $templateTxt = preg_replace($patterns, $replacements, preg_quote($templateTxt, '/'));
  
          return trim($templateTxt);
      }
docs: Prepares the matched template text for parsing by escaping known characters and removing excess whitespaces
  
  @param string $templateTxt ; The matched template contents
  @return string; The prepared clean template pattern