code: protected int pushTypeVariables () {
  		GenericType[] genericTypes = kryo.getGenerics().nextGenericTypes();
  		if (genericTypes == null) return 0;
  
  		int pop = kryo.getGenerics().pushTypeVariables(genericsHierarchy, genericTypes);
  		if (TRACE && pop > 0) trace("kryo", "Generics: " + kryo.getGenerics());
  		return pop;
  	}
docs: Prepares the type variables for the serialized type. Must be balanced with {@link #popTypeVariables(int)} if >0 is
  returned.