execAction.executable(GUtil.getOrDefault(executable, () -> Jvm.current().getJavadocExecutable()));
        execAction.args("@" + optionsFile.getAbsolutePath());

        options.contributeCommandLineOptions(execAction);

        return execAction;
    }

    public String getExecutable() {
        return executable;
    }

    public void setExecutable(String executable) {

    @Internal
    List<String> getSourceNames();

    void setSourceNames(@Nullable List<String> sourceNames);

    MinimalJavadocOptions sourceNames(String... sourceNames);

    void contributeCommandLineOptions(ExecSpec execHandleBuilder);

    }

    @Override
    public MinimalJavadocOptions jFlags(String... jFlags) {
        this.jFlags.addAll(Arrays.asList(jFlags));
        return this;
    }

    @Override
    public void contributeCommandLineOptions(ExecSpec execHandleBuilder) {
        execHandleBuilder
            .args(GUtil.prefix("-J", jFlags)) // J flags can not be set in the option file