TypeError: ModelName.forge(...).destroy is not a function

Question

I'm working on a API using node, where ModelName means the model built using bookshelf.js like this:

const bookshelf = require('./bookshelf')
const Intake = require('./intake')

const ModelName = bookshelf.Model.extend(
    {
        tableName: 'modelName',
        hasTimestamps: true,
        uuid: true,
        otherModel: function() {
            return this.hasOne(OtherModel)
        }
    },
    {
        dependents: ['otherModel']
    }
)

module.exports = ModelName 

and when testing the following funtion:

deleteModelName(Id) {
            try {
                return ModelName.forge({ id: Id }).destroy()
            } catch (err) {
                Logger.error('ModelNameService#deleteModelName :: failed to delete ModelName', > err.stack) 
             throw err
              }
            }

With this test:

describe('#deleteModelName', () => {
    it('should call deleteModelName', async () => {
           /*Creating a ModelName*/

        const deleteModelName = sandbox.stub()
        deleteModelName.resolves(CreatedModelName)
        const result = await ModelNameService.deleteModelName(ModelName.id)
        expect(result).to.be.undefined }}

I get this error:

TypeError: ModelName.forge(...).destroy is not a function