title: Laravel validation for field if "image/file" is selected?
body: <p>I have a field "image", type is <strong>file</strong> and need only to validate if image is selected, means it can be also empty.</p>
  
  <p>I tried it so: <code>'avatar' =&gt; 'mimes:jpeg,jpg,png,gif|max:100000',</code> but so it is also required.</p>
  
  <p>I tried still with parameters <code>present</code> and <code>sometimes</code> but the field is still required.</p>
  
  <p>How can I validate it only if image is selected?</p>