How can I set icons for the ContextMenu?

[Markus]

When implementing the ContextMenu the items do not contain the required icons.

I used the object notation from the example

{text: string, icon: string}

I tried to hard code the value in the html template

<kendo-contextmenu [target]="target">
      <kendo-menu-item text="My Web Site" icon="trash">
                    <kendo-menu-item text="images" icon="folder">

and I tried using a template and assigning the icons via [ngClass].

Nothing works.

I get an icon but it's always a downward chevron.

Any idea what might be causing this issue?
Could the icon font be overwritten?