code: public Optional<AddOnModel> getAddOn(final int serverID) {
          return addOns.stream()
                  .filter(addOn -> {
                      Optional<Integer> serverIDOpt = addOn.getPlugin().getDescriptor().getServerID();
                      return serverIDOpt.isPresent() && serverIDOpt.get() == serverID;
                  })
                  .findFirst();
      }
docs: Gets the {@link AddOnModel} that has the given id. The id is the serverID of the addOn.
  
  @param serverID The id is the serverID of the addOn.
  @return An optional wrapping the addOn. If the addOn was found the optional will not be empty and otherwise it
  will.