/**
     * Gets the user Toolchains source.
     *
     * @return the user Toolchains source or {@code null} if none
     */
    @Nonnull
    Optional<Source> getUserToolchainsSource();

    @Nonnull
    static ToolchainsBuilderRequest build(
            @Nonnull Session session,
            @Nullable Source installationToolchainsFile,
            @Nullable Source userToolchainsSource) {

        this.globalToolchainsSource = globalToolchainsSource;
        return this;
    }

    @Override
    public Source getUserToolchainsSource() {
        return userToolchainsSource;
    }

    @Override
    public ToolchainsBuildingRequest setUserToolchainsSource(Source userToolchainsSource) {
        this.userToolchainsSource = userToolchainsSource;

    /**
     * Gets the user toolchains source.
     *
     * @return The user toolchains source or {@code null} if none.
     */
    Source getUserToolchainsSource();

    /**
     * Sets the user toolchains source. If both user toolchains and a global toolchains are given, the user toolchains
     * take precedence.
     *

                            }))
                    .installationToolchainsSource(convert(request.getGlobalToolchainsSource()))
                    .userToolchainsSource(convert(request.getUserToolchainsSource()))
                    .build());

            return new DefaultToolchainsBuildingResult(
                    new PersistedToolchains(result.getEffectiveToolchains()), convert(result.getProblems()));