model.remove({}, (err, docs) => {
if (err) {
    console.log('remove error');
} else {
    console.log('remove success');
    model.insertMany(seeds, (insertError, insertedRecords) => {
        if (insertError) {
            console.log('insert error');
        } else {
            console.log('insert success');
        }
    });
}
});

model.collection.remove((removeError, removeResult) => {
   console.log('remove cb');
   model.collection.insert(seeds, (insertError, insertedRecords) => {
       console.log('insert cb');
   });
});

const schema = new Schema({
   name: {type: String, unique: true, index: true},
});

export default [
   {name: 'USA'},
   {name: 'Germany'},
   {name: 'France'}, ...