assertFalse(options.isNoTree());
        assertFalse(options.isNoIndex());
        assertFalse(options.isNoHelp());
        assertFalse(options.isNoNavBar());
        assertNull(options.getHelpFile());
        assertNull(options.getStylesheetFile());
        assertFalse(options.isSerialWarn());
        assertNull(options.getCharSet());
        assertNull(options.getDocEncoding());

     * <p>
     * javadoc -helpfile C:/user/myhelp.html java.awt
     */
    @Nullable @Optional @PathSensitive(NAME_ONLY) @InputFile
    public File getHelpFile() {
        return helpFile.getValue();
    }

    public void setHelpFile(@Nullable File helpFile) {
        this.helpFile.setValue(helpFile);
    }

Method <org.gradle.external.javadoc.StandardJavadocDocletOptions.getHelpFile()> does not have raw return type assignable to org.gradle.api.provider.Property in (StandardJavadocDocletOptions.java:0)