code: public static void notNullOrEmpty(File parameter, String name) throws IllegalArgumentException {
  		if (parameter == null || parameter.getPath().isEmpty()) {
  			throw new IllegalArgumentException(name + " path is null or empty.");
  		}
  	}
docs: Test if file parameter is not null and has not empty path.
  
  @param parameter invocation file parameter,
  @param name the name of invocation parameter.
  @throws IllegalArgumentException if <code>parameter</code> is null or its path is empty.