Dialog converter - Checkbox conversion

Hi

I am using the dialog converter tool 1.0 on AEM 6.0 SP3 for converting classic dialog checkbox into touch dialog checkbox. However the converted checkbox structure is different from classic.

Classic Structure:

<addbutton

     jcr:primaryType="cq:Widget"

     fieldLabel="Add Button"

     inputValue="true"

     name="./addbutton"

     type="checkbox"

     xtype="selection">

</addbutton>

Converted Touch UI Structure:

<addbutton

     jcr:primaryType="nt:unstructured"

     sling:resourceType="granite/ui/components/foundation/form/checkbox"

     name="./addbutton"

     text="Add Button"

     value="true"/>

<addbutton-delete

     jcr:primaryType="nt:unstructured"

     sling:resourceType="granite/ui/components/foundation/form/hidden"

     name="./addbutton@Delete"

     value="{Boolean}true"/>

I have searched for a rule at /libs/cq/dialogconversion/rules but cannot find any rule for checkbox.

Can anyone please help me understand how is the conversion being done ?