code: func (s *allInstancesSnapshot) FindInstances(ids []InstanceID) map[InstanceID]*ec2.Instance {
  	m := make(map[InstanceID]*ec2.Instance)
  	for _, id := range ids {
  		instance := s.instances[id]
  		if instance != nil {
  			m[id] = instance
  		}
  	}
  	return m
  }
docs: // FindInstances returns the instances corresponding to the specified ids.  If an id is not found, it is ignored.