mongoosastic population feature does not work

When I try to populate it does even save the document when I put population option. See example below,

const mongoosastic = require('mongoosastic');
const companyModel = require('./CompanyModel.js');

var Schema = mongoose.Schema;

var UserSchema = new Schema({
    Public: {
        fullName: {type: String, es_indexed: true},
        email: String,
        company: {
            type: mongoose.Schema.Types.ObjectId,
            ref: 'company',
            es_schema: companyModel, es_indexed:true, es_select: 'Info.CompanyName Info.CompanyLogo'
        }
    }

});

UserSchema.plugin(mongoosastic, {
  populate: [
    { path: 'Public.company', select: 'Info.CompanyName Info.CompanyLogo'}
  ]

})
var UserModel = mongoose.model('user', UserSchema);

module.exports = UserModel;

Can anybody help me with mongoostatic population feature. I have reffered this feature from the below link: https://github.com/mongoosastic/mongoosastic#indexing-mongoose-references

via Elvin Mammadov