code: func (ms *multiSource) Endpoints() ([]*endpoint.Endpoint, error) {
  	result := []*endpoint.Endpoint{}
  
  	for _, s := range ms.children {
  		endpoints, err := s.Endpoints()
  		if err != nil {
  			return nil, err
  		}
  
  		result = append(result, endpoints...)
  	}
  
  	return result, nil
  }
docs: // Endpoints collects endpoints of all nested Sources and returns them in a single slice.