Umbraco-CMS/src/Umbraco.Core/PropertyEditors/DropDownFlexibleConfiguration.cs

namespace Umbraco.Core.PropertyEditors
{
    internal class DropDownFlexibleConfiguration : ValueListConfiguration
    {
        [ConfigurationField("multiple", "Enable multiple choice", "boolean", Description = "When checked, the dropdown will be a select multiple / combo box style dropdown.")]
        public bool Multiple { get; set; }
    }
}