title: How to use a function defined in composition api in options api?
body: <p>I have a component and I'm using both composition api and options api. I want to use a function in options api which defined in composition api. How can i handle it?</p>
  <p>For example;</p>
  <pre><code>&lt;template&gt;
  &lt;button @click=&quot;cloneData&quot;&gt;Click Me&lt;/button&gt;
  &lt;/template&gt;
  &lt;script&gt;
  import { ref } from '@vue/composition-api'
  
  export default {
  methods: {
  cloneData()
  {
  compositionApiFunct()
  }
  },
  setup(){
  const compositionApiFunct = function() {
        console.log(&quot;testFunc&quot;)
      }
  return {
  compositionApiFunct
  }
  }
  }
  &lt;/script&gt; 
  </code></pre>
  <p>When I do this, I get the following error:</p>
  <p><code>Error in v-on handler: &quot;ReferenceError: compositionApiFunct is not defined&quot;</code></p>