return this;
    }

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

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

     *
     * @param userToolchainsSource The user toolchains source, may be {@code null} to disable user toolchains.
     * @return This request, never {@code null}.
     */
    ToolchainsBuildingRequest setUserToolchainsSource(Source userToolchainsSource);