code: func (s *Image) Setup() error {
  	if !s.docker.HasBin() {
  		return DockerBinNotFound(s.docker.binCmd)
  	}
  
  	if !s.Exists() {
  		if err := s.Pull(); err != nil {
  			return err
  		}
  	}
  
  	return nil
  }
docs: // Setup check if Docker binary is available and pull current image from Docker
  // repository in case it is not already available.