code: func PlatformSpecFromOCI(p *ocispec.Platform) *manifestlist.PlatformSpec {
  	if p == nil {
  		return nil
  	}
  	return &manifestlist.PlatformSpec{
  		Architecture: p.Architecture,
  		OS:           p.OS,
  		OSVersion:    p.OSVersion,
  		OSFeatures:   p.OSFeatures,
  		Variant:      p.Variant,
  	}
  }
docs: // PlatformSpecFromOCI creates a platform spec from OCI platform