class InstantiationSet {

    private List<Instantiation> instantiations;

    public boolean allInferenceVariablesAreResolved(BoundSet boundSet) {
        throw new UnsupportedOperationException();
    }

    public static InstantiationSet empty() {
        return EMPTY;
    }

    private static final InstantiationSet EMPTY = new InstantiationSet();

    private InstantiationSet() {
        instantiations = new LinkedList<>();
    }

    public InstantiationSet withInstantiation(Instantiation instantiation) {<FILL_FUNCTION_BODY>}

    public boolean isEmpty() {
        return instantiations.isEmpty();
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;

        InstantiationSet that = (InstantiationSet) o;

        return instantiations.equals(that.instantiations);
    }

    @Override
    public int hashCode() {
        return instantiations.hashCode();
    }

    @Override
    public String toString() {
        return "InstantiationSet{" +
                "instantiations=" + instantiations +
                '}';
    }

    public ResolvedType apply(ResolvedType type) {
        for (Instantiation instantiation : instantiations) {
            type = type.replaceTypeVariables(instantiation.getInferenceVariable().getTypeParameterDeclaration(), instantiation.getProperType());
        }
        return type;
    }
}

        InstantiationSet newInstance = new InstantiationSet();
        newInstance.instantiations.addAll(this.instantiations);
        newInstance.instantiations.add(instantiation);
        return newInstance;
    
<no_super_class>