code: public static boolean isUpdateRequired(File sourceFile, File targetFile) {
  	if (targetFile.exists()) {
  	    if (targetFile.lastModified() > sourceFile.lastModified()) {
  		return false;
  	    }
  	}
  	return true;
      }
docs: This method checks for the requirement for an update.
  
  If a the target file exists and the modification time is greater than the
  modification time of the source file, we do not need to analyze something.
  
  @param sourceFile
  is the source file where it is intended to be copied from.
  @param targetFile
  is the file to which everything is to be copied to.
  @return <code>true</code> is returned in case of a required update.
  <code>false</code> is returned otherwise.