code: public static File exists(File file) {
  		Validate.notNull(file);
  		if(!file.exists())
  			throw new ParameterException("\""+file+"\" does not exist!");
  		return file;
  	}
docs: Checks if the given file exists.<br>
  @param file The file to validate.
  @return The validated file reference.
  @throws ParameterException if the file does not exist.