code: public Long marketplace_createListing(Boolean showOnProfile, MarketplaceListing attrs)
      throws FacebookException, IOException {
      T result =
        this.callMethod(FacebookMethod.MARKETPLACE_CREATE_LISTING, 
                        new Pair<String, CharSequence>("show_on_profile", showOnProfile ? "1" : "0"),
                        new Pair<String, CharSequence>("listing_id", "0"),
                        new Pair<String, CharSequence>("listing_attrs", attrs.jsonify().toString()));
      return this.extractLong(result);
    }
docs: Create a marketplace listing
  @param showOnProfile whether the listing can be shown on the user's profile
  @param attrs the properties of the listing
  @return the id of the created listing
  @see MarketplaceListing
  @see <a href="http://wiki.developers.facebook.com/index.php/Marketplace.createListing">
  Developers Wiki: marketplace.createListing</a>