title: How to make VariableSized GridView Item?
body: <p>I would like to do a VariableSizedWrapGrid for the item within the wrapgrid. 
  <img src="https://i.stack.imgur.com/2lX2Z.png" alt="enter image description here"></p>
  
  <p>Something like this. 
  The group title above store all the child item show on photo. 
  After scroll to right hand, another group title with the child shown as below. 
   Anyone have any idea how to do so?</p>
  
  <p>I was able to display group title with child item as below. The only things i unable to achieve is the variable size of the child item. </p>