code: func outMorphism(tags []string, via ...interface{}) morphism {
  	return morphism{
  		Reversal: func(ctx *pathContext) (morphism, *pathContext) { return inMorphism(tags, via...), ctx },
  		Apply: func(in shape.Shape, ctx *pathContext) (shape.Shape, *pathContext) {
  			return shape.Out(in, buildVia(via...), ctx.labelSet, tags...), ctx
  		},
  		tags: tags,
  	}
  }
docs: // outMorphism iterates forward one RDF triple or via an entire path.