<mat-icon #block id="block" fontSet="deja-icons" fontIcon="block"></mat-icon>
<div #content id="content"></div>
<div id="block" #block>
    <mat-icon #block fontSet="deja-icons" fontIcon="block"></mat-icon>
</div>
<div #content id="content"></div>

Fix icon elemnt null pointer
fix(DejaMouseDragDrop): Fix icon elemnt null pointer
