code: func (s *CapSet) Supports(id CapID) error {
  	err := &CapError{ID: id}
  	c, ok := s.list.m[id]
  	if !ok {
  		return errors.WithStack(err)
  	}
  	err.Definition = &c
  	state, ok := s.set[string(id)]
  	if !ok {
  		return errors.WithStack(err)
  	}
  	err.State = state
  	if !state.Enabled {
  		return errors.WithStack(err)
  	}
  	return nil
  }
docs: // Supports returns an error if capability is not supported