title: This is undefined in Vue, using debounce method
body: <p>I know that using the arrow syntax for a method will cause 'this' to not be mapped to the Vue instance, however in my example I'm using lodash.debounce, and as far as I know I'm not using the arrow syntax here?</p>
  
  <p><strong>Returns Cannot read property '$emit' of undefined</strong></p>
  
  <pre><code>methods: {
    onChange: debounce(function(el) {
      this.$emit('change', el.target.value)
    }, 1000)
  }
  </code></pre>
  
  <p><strong>is there a syntax error in the way I'm writing this debounce function without arrow notation?</strong></p>