code: func InitModels() {
  	index := mgo.Index{
  		Key:      []string{"key"},
  		Unique:   true,
  		DropDups: false,
  	}
  
  	db.EnsureIndex(mongoOngoingPhonenumberValidationCollectionName, index)
  	db.EnsureIndex(mongoOngoingEmailAddressValidationCollectionName, index)
  
  	automaticExpiration := mgo.Index{
  		Key:         []string{"createdat"},
  		ExpireAfter: time.Second * 60 * 10,
  		Background:  true,
  	}
  	db.EnsureIndex(mongoOngoingPhonenumberValidationCollectionName, automaticExpiration)
  
  	automaticExpiration = mgo.Index{
  		Key:         []string{"createdat"},
  		ExpireAfter: time.Second * 3600 * 48,
  		Background:  true,
  	}
  	db.EnsureIndex(mongoOngoingEmailAddressValidationCollectionName, automaticExpiration)
  
  	index = mgo.Index{
  		Key:      []string{"username", "phonenumber"},
  		Unique:   true,
  		DropDups: true,
  	}
  	db.EnsureIndex(mongoValidatedPhonenumbers, index)
  
  	index = mgo.Index{
  		Key:      []string{"phonenumber"},
  		Unique:   true,
  		DropDups: true,
  	}
  	db.EnsureIndex(mongoValidatedPhonenumbers, index)
  
  	index = mgo.Index{
  		Key:      []string{"username", "emailaddress"},
  		Unique:   true,
  		DropDups: true,
  	}
  	db.EnsureIndex(mongoValidatedEmailAddresses, index)
  	index = mgo.Index{
  		Key:      []string{"emailaddress"},
  		Unique:   true,
  		DropDups: true,
  	}
  	db.EnsureIndex(mongoValidatedEmailAddresses, index)
  
  }
docs: //InitModels initialize models in mongo, if required.