code: func NewResultReader(qs QuadStore, it Iterator) quad.ReadSkipCloser {
  	if it == nil {
  		it = qs.QuadsAllIterator()
  	}
  	return &quadReader{qs: qs, it: it}
  }
docs: // NewResultReader creates a quad reader for a given QuadStore and iterator.
  // If iterator is nil QuadsAllIterator will be used.
  //
  // Only quads returned by iterator's Result will be used.
  //
  // Iterator will be closed with the reader.