code: func (m *Manager) GetByUsernameAndAZP(username, azp string) (*Identifier, error) {
  	var idObj Identifier
  
  	if err := m.getIdentifierCollection().Find(bson.M{"username": username, "azp": azp}).One(&idObj); err != nil {
  		return nil, err
  	}
  
  	return &idObj, nil
  }
docs: // GetByUsernameAndAZP returns the Identifier object for this username and azp combo