How to specify radio buttons in baseFieldDefinitions? In the baseFieldDefinitions method of my custom entity, I see I can provide a checkbox list with code like...

$fields['my_field'] = BaseFieldDefinition::create("list_string")
      -&gt;setSetting('allowed_values', $$my_options)
      -&gt;setLabel('My Field')
      -&gt;setRequired(FALSE)
      -&gt;setCardinality(-1)
      -&gt;setDisplayOptions('form', array(
        'type' =&gt; 'options_buttons',
        'weight' =&gt; 5
      ))
      -&gt;setDisplayConfigurable('form', TRUE)
      -&gt;setDisplayConfigurable('view', TRUE);


But how would I specify radio buttons so the user can make only one selection from the list?
The radios/checkboxes are displayed based on the field's cardinality:


If the field can store more than one (e.g., unlimited: -&gt;setCardinality(-1), or 2,3,etc. -&gt;setCardinality(2), -&gt;setCardinality(3), etc.), it will be displayed as checkboxes.
If the field can store only one (i.e. -&gt;setCardinality(1)), it will be displayed as radio buttons.