code: public boolean addProperty(String propertyName, String property) {
          boolean ret = this.properties.containsKey(propertyName);
          this.properties.put(propertyName, property);
          return ret;
      }
docs: Used to add a new property to the offering
  
  @param propertyName the name of the property
  @param property the value of the property
  @return true if the property was already present (and it has been replaced), false otherwise