code: func WithoutExportCache() ConstraintsOpt {
  	return constraintsOptFunc(func(c *Constraints) {
  		// ExportCache with value false means to disable exporting
  		c.Metadata.ExportCache = &pb.ExportCache{Value: false}
  	})
  }
docs: // WithoutExportCache sets results for this vertex to be not exported with
  // the cache