Ember access variable inside Mixin

import Ember from 'ember';
import myConst from '../utils/constants';

export default Ember.Mixin.create(myConst, {
  getFieldId: function(productCode) {
        console.log(myConst.MY_METHODS.FIELD_ID); //Not able to access this
  }
});

My constants.js looks like

var myConst = {};

myConst.MY_METHODS = {
        FIELD_ID: "fieldId"
};

export default myConst;

I am unable to access myConst inside the mixin. What am I doing wrong ?