Angularjs parsedNgModelAssign is not a function?

It is one of the basic problem, but if you search in google probably you will find a lot of solutions which is not related. When you have input field with getterSetter, and you didn’t give the function name correctly then you will get this error:

TypeError: parsedNgModelAssign is not a function
    at NgModelController.$$setOptions.ngModelSet (angular.js:20414)
    at NgModelController.$$writeModelToScope (angular.js:20863)
    at writeToModelIfNeeded (angular.js:20857)
    at angular.js:20851

Example field:

<textarea
        class="form-control"
        name="test"
        cols="5"
        data-ng-model="ctrl.testGetterSetter(test)"
        data-ng-model-options="{getterSetter:true}"
        data-required>
</textarea>

Basicly this problem appears if data-ng-model="ctrl.testGetterSetter(test)" can’t find the testGetterSetter function.