Trying to add 'disambiguate-add-year-suffix' and 'collapse'

my-first-style.xml

<?xml version="1.0" encoding="UTF-8"?>
<style xmlns="http://purl.org/net/xbiblio/csl" version="1.0"
class="in-text">
  <info>
    <title>My First Style</title>
    <id>my-first-style</id>
    <updated>2008-10-29T21:01:24+00:00</updated>
  </info>
  <macro name="author-short">
    <names variable="author">
      <name form="short"/>
    </names>
  </macro>
  <macro name="author">
    <names variable="author">
      <name name-as-sort-order="all" initialize-with=". "/>
    </names>
  </macro>
  <macro name="issued">
    <date variable="issued">
      <date-part name="year"/>
    </date>
  </macro>
  <citation et-al-min="3" et-al-use-first="1" disambiguate-add-year-suffix="true" collapse="year">
    <sort>
      <key macro="issued"/>
      <key macro="author-short"/>
    </sort>
    <layout prefix="(" suffix=")" delimiter="; ">
      <text macro="author-short"/>
      <text macro="issued" prefix=" "/>
    </layout>
  </citation>
  <bibliography>
    <sort>
      <key macro="author"/>
      <key macro="issued"/>
    </sort>
    <layout suffix=".">
      <group delimiter=" ">
        <text macro="author"/>
        <text macro="issued" prefix="(" suffix=")"/>
        <text variable="title" suffix="."/>
        <text variable="container-title" font-style="italic"/>
      </group>
      <group prefix=", ">
        <text variable="volume" suffix=":"/>
        <text variable="page"/>
      </group>
    </layout>
  </bibliography>
</style>