class FieldWidget

class FieldWidget extends Plugin {
    
    /**
     * The plugin ID.
     *
     * @var string
     */
    public $id;
    
    /**
     * The human-readable name of the widget type.
     *
     * @var \Drupal\Core\Annotation\Translation
     *
     * @ingroup plugin_translatable
     */
    public $label;
    
    /**
     * A short description of the widget type.
     *
     * @var \Drupal\Core\Annotation\Translation
     *
     * @ingroup plugin_translatable
     */
    public $description;
    
    /**
     * The name of the widget class.
     *
     * This is not provided manually, it will be added by the discovery mechanism.
     *
     * @var string
     */
    public $class;
    
    /**
     * An array of field types the widget supports.
     *
     * @var array
     */
    public $field_types = [];
    
    /**
     * Does the field widget handles multiple values at once.
     *
     * @var bool
     */
    public $multiple_values = FALSE;
    
    /**
     * An integer to determine weight of this widget relative to other widgets.
     *
     * Other widgets are in the Field UI when selecting a widget for a given
     * field.
     *
     * This property is optional and it does not need to be declared.
     *
     * @var int
     */
    public $weight = NULL;

}