public Joiner pushSet(String alias){
  if (mapBuilder == null) {
    mapBuilder=new MapBuilder(this);
  }
  mapBuilder.addTerm(MapBuilderTermType.SET,lookupAlias(alias),alias);
  return this;
}

public Joiner pushSet ( String alias ) { if ( mapBuilder == null ) { mapBuilder = new MapBuilder ( this ) ; } mapBuilder . addTerm ( MapBuilderTermType . SET , lookupAlias ( alias ) , alias ) ; return this ; }
pushes a set < t > for use by the map builder .
