Creating a simple custom comboBox or selectBox

Hi everyone,
I’m trying to add some cutomized fields to the properties panel, but I’m facing a problem when try to create a comboBox or selectBox. I cannot understand how to put the get and set method on the factory.

Here is the part of the code:
{
EntryFactory.selectBox({

            id: 'id_tipo_prazo',

            label: this.translate('Tipo Prazo'),

            modelProperty: 'id_tipo_prazo',

            selectOptions: [{

                value: '1',

                name: 'Sem Validade'

              },

              {

                value: '2',

                name: 'Data Processo'

              },

              {

                value: '3',

                name: 'Data Tarefa'

              },

              {

                value: '4',

                name: 'Data Informada'

              }],

              get: function (element, node) {

              },

    

              set: function (element, values, node) {

              }

            }),

}
If anyone has a tip to help me, I appreciate.

Thanks