/**
  * Returns the identifiers of the WantedFixed elements
  *
  * @return the string identifying the WantedFixed
  */
 public Collection<String> getFixedNames() {
   return fixed.getElementNames();
 }
 /**
  * Returns the identifiers of the WantedFurniture
  *
  * @return the string identifying the WantedFurnitures
  */
 public Collection<String> getFurnitureNames() {
   return furniture.getElementNames();
 }