protected void mergeProperties(Properties aTarget,Properties aSource){
  for (  Object key : aSource.keySet()) {
    if (!aTarget.containsKey(key)) {
      aTarget.put(key,aSource.get(key));
    }
  }
}

protected void mergeProperties ( Properties aTarget , Properties aSource ) { for ( Object key : aSource . keySet ( ) ) { if ( ! aTarget . containsKey ( key ) ) { aTarget . put ( key , aSource . get ( key ) ) ; } } }
copy all properties that not already exist in target from source .
