code: public static Resource toExactResource(Resource res) {
  	res = getCanonicalResourceEL(res);
  	if (res.getResourceProvider().isCaseSensitive()) {
  	    if (res.exists()) return res;
  	    return _check(res);
  
  	}
  	return res;
      }
docs: translate the path of the file to a existing file path by changing case of letters Works only on
  Linux, because
  
  Example Unix: we have a existing file with path "/usr/virtual/myFile.txt" now you call this
  method with path "/Usr/Virtual/myfile.txt" the result of the method will be
  "/usr/virtual/myFile.txt"
  
  if there are more file with rhe same name but different cases Example: /usr/virtual/myFile.txt
  /usr/virtual/myfile.txt /Usr/Virtual/myFile.txt the nearest case wil returned
  
  @param res
  @return file